Castle in the context of Farnham Castle

The Swallow's Nest (Russian: Ласточкино гнездо, romanized: Lastochkino gnezdo, Ukrainian: Ластівчине гніздо, romanized: Lastivchyne hnizdo) is a decorative castle located at Gaspra, a small spa town between Yalta and Alupka on the Crimean peninsula. It was built between 1911 and 1912, on top of the 40-metre-high (130 ft) Aurora Cliff, in a Neo-Gothic design by the Russian architect Leonid Sherwood for Pavel Leonardovich von Steingel, a Russian noble with German roots.

The castle overlooks the Cape of Ai-Todor on the Black Sea coast and is located near the remains of the Roman castrum of Charax. The Swallow's Nest is one of the most popular visitor attractions in Crimea, having become the symbol of Crimea's southern coastline.

A citadel is the most fortified area of a town or city. It may be a castle, fortress, or fortified center. The term is a diminutive of city, meaning "little city", because it is a smaller part of the city of which it is the defensive core.

In a fortification with bastions, the citadel is the strongest part of the system, sometimes well inside the outer walls and bastions, but often forming part of the outer wall for the sake of economy. It is positioned to be the last line of defence, should the enemy breach the other components of the fortification system.

Rosenborg Castle (Danish: Rosenborg Slot) is a renaissance castle in Copenhagen, Denmark. The castle was originally built as a country summerhouse in 1606 and is an example of Christian IV's many architectural projects. It was built in the Dutch Renaissance style, typical of Danish buildings during this period, and has been expanded several times, finally evolving into its present condition by the year 1624. Architects Bertel Lange and Hans van Steenwinckel the Younger are associated with the structural planning of the castle.

Edo Castle (江戸城, Edo-jō) is a flatland castle that was built in 1457 by Ōta Dōkan in Edo, Toshima District, Musashi Province. In modern times it is part of the Tokyo Imperial Palace in Chiyoda, Tokyo, and is therefore also known as Chiyoda Castle (千代田城, Chiyoda-jō).Tokugawa Ieyasu established the Tokugawa shogunate there, and it was the residence of the shōgun and the headquarters of the military government during the Edo period (1603–1867) in Japanese history. After the resignation of the shōgun and the Meiji Restoration, it became the Tokyo Imperial Palace. Some moats, walls and ramparts of the castle survive to this day. However, the grounds were more extensive during the Edo period, with Tokyo Station and the Marunouchi section of the city lying within the outermost moat. It also encompassed Kitanomaru Park, the Nippon Budokan Hall and other current landmarks of the surrounding area.

Gouda (Dutch pronunciation: [ˈɣʌudaː] ) is a city and municipality in the west of the Netherlands, between Rotterdam and Utrecht, in the province of South Holland. Gouda has a population of 75,000 and is famous for its Gouda cheese, stroopwafels, many grachten, smoking pipes, and its 15th-century city hall. Its array of historic churches and other buildings makes it a very popular day-trip destination.

In the Middle Ages the Van der Goude [nl] family founded a settlement at the location of the current city and built a fortified castle alongside the banks of the Gouwe River, from which the family and the city took their names. Locals long called the settlement Ter Goude, or Tergou or Tergouw [nl] for short.The area, originally marshland, developed over the course of two centuries. By 1225, a canal was linked to the Gouwe and its estuary became a harbour. In 1272 Floris V, Count of Holland granted the city city rights.

A tower is a tall structure, taller than it is wide, often by a significant factor. Towers are distinguished from masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting structures.

Towers are specifically distinguished from buildings in that they are built not to be habitable but to serve other functions using the height of the tower. For example, the height of a clock tower improves the visibility of the clock, and the height of a tower in a fortified building such as a castle increases the visibility of the surroundings for defensive purposes. Towers may also be built for observation, leisure, or telecommunication purposes. A tower can stand alone or be supported by adjacent buildings, or it may be a feature on top of a larger structure or building.

The Louvre Palace (French: Palais du Louvre, [palɛ dy luvʁ]), often referred to simply as the Louvre, is an iconic French palace located on the Right Bank of the Seine in Paris, occupying a vast expanse of land between the Tuileries Gardens and the church of Saint-Germain l'Auxerrois. Originally a defensive castle, it has served several government-related functions in the past, including intermittently as a royal residence between the 14th and 18th centuries. It is now mostly used by the Louvre Museum, which first opened there in 1793.

While this area along the Seine had been inhabited for thousands of years, the Louvre's history starts around 1190 with its first construction as the Louvre Castle defending the western front of the Wall of Philip II Augustus, the then new city-wall of Paris. The Louvre's oldest section still standing above ground, its palatial Lescot Wing, dates from the late 1540s, when Francis I started the replacement of the greatly expanded medieval castle with a new design inspired by classical antiquity and Italian Renaissance architecture. Most parts of the current building were constructed in the 17th and 19th centuries. In the late 20th century, the Grand Louvre project increased visitor access and gallery space, including by adding the Louvre Pyramid in the courtyard Cour Napoléon.

The Louvre Castle (French: Château du Louvre), also referred to as the Medieval Louvre (French: Louvre médiéval), was a castle (French: château fort) begun by Philip II of France on the right bank of the Seine, to reinforce the city wall he had built around Paris. Over time, it was expanded but was generally demolished above ground in stages between 1528 and 1660 to make way for expanding the Louvre Palace, while some parts of the castle's foundations were incorporated in construction of the later palace.

The Château des Baux is a ruined fortified castle built during the 10th century, located in Les Baux-de-Provence, Bouches-du-Rhône, southern France.

Manorialism, also known as seigneurialism, the manor system or manorial system, was the method of land ownership (or "tenure") in parts of Europe, notably France and later England, during the Middle Ages. Its defining features included a large, sometimes fortified manor house or castle in which the lord of the manor and his dependants lived and administered a rural estate, and a population of labourers or serfs who worked the surrounding land to support themselves and the lord. These labourers fulfilled their obligations with labour time or in-kind produce at first, and later by cash payment as commercial activity increased. Manorialism was part of the feudal system.

Manorialism originated in the Roman villa system of the Late Roman Empire, and was widely practised in medieval western Europe and parts of central Europe. An essential element of feudal society, manorialism was slowly replaced by the advent of a money-based market economy and new forms of agrarian contract.

The Ridderzaal (Dutch pronunciation: [ˈrɪdərzaːl]; English: Hall of Knights) is the main building of the 13th-century inner square of the former castle of the counts of Holland called Binnenhof (English: Inner Court) at the address Binnenhof 11 in The Hague, Netherlands. It is used for the annual state opening of Parliament on Prinsjesdag, when the Dutch monarch drives to Parliament in the Golden Coach and delivers the speech from the throne. It is also used for official royal receptions, and inter-parliamentary conferences.

Due to the restoration of the Golden Coach and some controversy surrounding images on the left panel, portraying Hulde der Koloniën (Tribute from the colonies), the Glass Coach is used on Prinsjesdag since 2015.

The Tower of London, officially His Majesty's Royal Palace and Fortress of the Tower of London, is a historic citadel and castle on the north bank of the River Thames in London, England. It lies within the London Borough of Tower Hamlets, which is separated from the eastern edge of the square mile of the City of London by the open space known as Tower Hill. It was founded toward the end of 1066 as part of the Norman Conquest. The White Tower, which gives the entire castle its name, was built by William the Conqueror in 1078 and was initially a resented symbol of oppression, inflicted upon London by the new Norman ruling class. The castle was also used as a prison from 1100 (Ranulf Flambard, Bishop of Durham) until 1952 (the Kray twins), although that was not its primary purpose. A grand palace early in its history, it served as a royal residence. As a whole, the Tower is a complex of several buildings set within two concentric rings of defensive walls and a moat. There were several phases of expansion, mainly under kings Richard I, Henry III, and Edward I in the 12th and 13th centuries. The general layout established by the late 13th century remains despite later activity on the site.

The Tower of London has played a prominent role in English history. It was besieged several times, and controlling it has been important to controlling the country. The Tower has served variously as an armoury, a treasury, a menagerie, the home of the Royal Mint, a public record office, and the home of the Crown Jewels of England. From the early 14th century until the reign of Charles II in the 17th century, the monarch would traditionally prepare for several nights at the Tower, and lead a procession from there to Westminster Abbey for their coronation. In the absence of the monarch, the Constable of the Tower was in charge of the castle. This was a powerful and trusted position in the medieval period. In the late 15th century, the Princes in the Tower were housed at the castle when they mysteriously disappeared, presumed murdered. Under the Tudors, the Tower was used less as a royal residence, and despite attempts to refortify and repair the castle, its defences lagged behind developments to deal with artillery.

The Royal Castle in Warsaw (Polish: Zamek Królewski w Warszawie [ˈzamɛk kruˈlɛfskʲi v varˈʂavjɛ]) is a state museum and a national historical monument, which formerly served as the official royal residence of several Polish monarchs. The personal offices of the king and the administrative offices of the royal court were located in the Castle from the 16th century until the final partition of Poland in 1795. Situated in the Castle Square, at the entrance to the Old Town, the Royal Castle holds a significant collection of Polish and European art.

The Royal Castle witnessed many notable events in Poland's history; the Constitution of 3 May 1791, first of its type in Europe and the world's second-oldest codified national constitution, was drafted here by the Four-Year Parliament. The edifice was redesigned into a neoclassical style following the partitions of Poland. Under the Second Polish Republic (1918–1939), it was the seat of the Polish head of state and president. The Second World War brought complete destruction to the building; in September 1939 it was targeted and ignited by Luftwaffe fighter aircraft, and then detonated by the Nazis after the failed Warsaw Uprising in 1944.

Savonlinna Opera Festival (Finnish: Savonlinnan oopperajuhlat) is held annually in the city of Savonlinna in Finland. The Festival takes place at the medieval Olavinlinna (St. Olaf's Castle), built in 1475. The castle is located amid spectacular lake scenery.

Kronborg (Danish pronunciation: [ˈkʰʁoːnˌpɒˀ]) is a castle and historical stronghold in the town of Helsingør, Denmark. Immortalised as Elsinore in William Shakespeare's play Hamlet, Kronborg is one of the most important Renaissance castles in Northern Europe. It was inscribed on the UNESCO World Heritage List in 2000.

The castle is situated on the extreme northeastern tip of the island of Zealand at the narrowest point of the Øresund, the sound between present Denmark and the provinces of present Sweden. The latter were under Danish control at the time the castle was built. In this part, the sound is only 4 kilometres (2.5 mi) wide, hence the strategic importance of maintaining a coastal fortification at this location commanding one of the few outlets of the Baltic Sea.

In fortification architecture, a rampart is a length of embankment or wall forming part of the defensive boundary of a castle, hillfort, settlement or other fortified site. It is usually broad-topped and made of excavated earth and/or masonry.

Paramonga was an important city constructed at the border of the former Kingdom of Chimor in Peru during the late Intermediate Period (AD 1200 to 1400), whose capital was the metropolis of Chan Chan.

Paramonga is located on the Fortaleza River, close to the town of Pativilca to the north of Lima. It is said that it was an important religious settlement, similar to Pachacamac. It is named after the nearby modern town of Paramonga, as its original name is unknown. Paramonga is often called a fortress due to its staggered pyramid of four levels of enormous proportions constructed on a hill, which somewhat resembles a European medieval castle, though it was built prior to Spanish colonization of the area.

A moat is a deep, broad ditch dug around a castle, fortification, building, or town, historically to provide it with a preliminary line of defence. Moats can be dry or filled with water. In some places, moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices. In older fortifications, such as hillforts, they are usually referred to simply as ditches, although the function is similar. In later periods, moats or water defences may be largely ornamental. They could also act as a sewer.

A fish pond or fishpond is a controlled pond, small artificial lake or retention basin that is stocked with fish and is used in aquaculture for fish farming, for recreational fishing, or for ornamental purposes.

Fish ponds are a classical garden feature in East Asian residence, such as the Classical Gardens of Suzhou of China, the Imperial Palace of Japan and the Gyeongbokgung Palace of South Korea. In Medieval Europe, it was also typical for monasteries and castles (small, partly self-sufficient communities) to have a fish pond.