Brandenburg Gate in the context of "Unter den Linden"

An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not an explicit agreement has been worked out among them. Members of an alliance are called allies. Alliances form in many settings, including political alliances, military alliances, and business alliances.

In ancient Greek architecture, a propylon (/ˈprɒpɪlɒn/ or /ˈprɒupɪlɒn/; Ancient Greek πρόπυλον própulon)—also called a propylaeum (/prɒpɪˈliːəm/, a Latinized form of προπύλαιον propúlaion), and frequently referred to by the plural forms propyla and propylaea—is a monumental gateway. It serves as a partition, separating the secular and religious parts of a city. The prototypical Greek example is the propylaea that served as the entrance to the Acropolis of Athens. The Greek Revival Brandenburg Gate of Berlin and the Propylaea in Munich both evoke the central portion.

Greek Revival architecture is a style that began in the middle of the 18th century but which particularly flourished in the late 18th and early 19th centuries, predominantly in northern Europe, the United States, and Canada, and Greece following that nation's independence in 1821. It revived many aspects of the forms and styles of ancient Greek architecture, including the Greek temple. A product of Hellenism, Greek Revival architecture is looked upon as the last phase in the development of Neoclassical architecture, which was drawn from Roman architecture. The term was first used by Charles Robert Cockerell in a lecture he gave as an architecture professor at the Royal Academy of Arts in London in 1842.

With newfound access to Greece and Turkey, or initially to the books produced by the few who had visited the sites, archaeologist–architects of the period studied the Doric and Ionic orders. Despite its universality rooted in ancient Greece, the Greek Revival idiom was considered an expression of local nationalism and civic virtue in each country that adopted it, and freedom from the lax detail and frivolity that then characterized the architecture of France and Italy, two countries where the style never really took architecturally. Greek Revival architecture was embraced in Great Britain, Germany, and the United States, where the idiom was regarded as being free from ecclesiastical and aristocratic associations and was appealed to each country's emerging embrace of classical liberalism.

A nonbuilding structure, often referred to simply as a structure, is any built structure or construction structure that is not a building, i.e. not designed for continuous human occupancy. The term is particularly used by architects, structural engineers, and mechanical engineers to distinguish load-bearing structures not designed for continuous human occupancy.

Mitte (German: [ˈmɪtə] ) is the first and most central borough of Berlin. The borough consists of six sub-entities: Mitte proper, Gesundbrunnen, Hansaviertel, Moabit, Tiergarten and Wedding.

It is one of the two boroughs (the other being Friedrichshain-Kreuzberg) which were formerly divided between East Berlin and West Berlin. Mitte encompasses Berlin's historic core and includes some of the most important tourist sites of Berlin like the Reichstag and Berlin Hauptbahnhof, Checkpoint Charlie, Museum Island, the TV tower, Brandenburg Gate, Unter den Linden, Potsdamer Platz, Alexanderplatz and Fotografiska Berlin. The latter seven of which were in former East Berlin.

The history of Berlin starts with its foundation in the 12th century. It became the capital of the Margraviate of Brandenburg in 1237, and later of Brandenburg-Prussia, and the Kingdom of Prussia. Prussia grew about rapidly in the 18th and 19th centuries and formed the basis of the German Empire in 1871. The empire would survive until 1918 when it was defeated in World War I.

After 1900 Berlin became a major world city, known for its leadership roles in science, the humanities, music, museums, higher education, government, diplomacy and military affairs. It also had a role in manufacturing and finance.

Potsdamer Platz (German: [ˈpɔtsdamɐ plats] , Potsdam Square) is a public square and traffic intersection in the center of Berlin, Germany, lying about 1 km (1,100 yd) south of the Brandenburg Gate and the Reichstag (German Parliament Building), and close to the southeast corner of the Tiergarten park. It is named after the city of Potsdam, some 25 km (16 mi) to the south west, and marks the point where the old road from Potsdam passed through the city wall of Berlin at the Potsdam Gate. Initially, the open area near the city gate was used for military drills and parades. In the 19th into the 20th century, it developed from an intersection of suburban thoroughfares into the most bustling traffic intersection in Europe. The area was totally destroyed during World War II and then left desolate during the Cold War era when the Berlin Wall bisected it. Following German reunification in 1990, Potsdamer Platz underwent extensive redevelopment throughout the 1990s and early 2000s. Today, it is a bustling commercial and cultural hub featuring corporate offices, retail spaces, restaurants, cinemas, and hotels.