Cologne in the context of "Communist Correspondence Committee"

Luxembourg (Luxembourgish: Lëtzebuerg; French: Luxembourg; German: Luxemburg), also known as Luxembourg City (Luxembourgish: Stad Lëtzebuerg or d'Stad; French: Ville de Luxembourg; German: Stadt Luxemburg or Luxemburg-Stadt), is the capital city of Luxembourg and the country's most populous commune. Standing at the confluence of the Alzette and Pétrusse rivers in southern Luxembourg, the city lies in the center of Western Europe, situated 213 km (132 mi) by road from Brussels and 209 km (130 mi) from Cologne. The city contains Luxembourg Castle, established by the Franks in the Early Middle Ages, around which a settlement developed.

As of 31 December 2024, Luxembourg City has a population of 136,208 inhabitants, which is more than three times the population of the country's second most populous commune (Esch-sur-Alzette). The population consists of 160 nationalities. Foreigners represent 70.1% of the city's population, whilst Luxembourgers represent 29.9% of the population, making it the commune with the highest proportion of foreign residents in Luxembourg.

The Rhine-Ruhr metropolitan region (German: Metropolregion Rhein-Ruhr) is the largest metropolitan region in Germany, with over ten million inhabitants. A polycentric conurbation with several major urban concentrations, the region covers an area of 7,110 square kilometres (2,750 sq mi), entirely within the federal state of North Rhine-Westphalia. The Rhine-Ruhr metropolitan region spreads from the Ruhr area (Dortmund-Bochum-Essen-Duisburg) in the north to the urban areas of the cities of Mönchengladbach, Düsseldorf (the state capital), Wuppertal, Leverkusen, Cologne (the region's largest and Germany's fourth largest city), and Bonn in the south. The location of the Rhine-Ruhr at the heart of the European Blue Banana makes it well connected to other major European cities and metropolitan areas such as the Randstad, the Flemish Diamond and the Frankfurt Rhine Main Region.

The metropolitan area is named after the Rhine and Ruhr rivers, which are the region's defining geographical features and historically its economic backbone.

Construction is the process involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the asset is built and ready for use. Construction also covers repairs and maintenance work, any works to expand, extend and improve the asset, and its eventual demolition, dismantling or decommissioning.

The construction industry contributes significantly to many countries' gross domestic products (GDP). Global expenditure on construction activities was about $4 trillion in 2012. In 2022, expenditure on the construction industry exceeded $11 trillion a year, equivalent to about 13 percent of global GDP. This spending was forecasted to rise to around $14.8 trillion in 2030.

The Electorate of Cologne (German: Kurfürstentum Köln), sometimes referred to as Electoral Cologne (German: Kurköln), was an ecclesiastical principality of the Holy Roman Empire that existed from the 10th to the early 19th century. It consisted of the Hochstift—the temporal possessions—of the archbishop of Cologne, and was ruled by him in his capacity as prince-elector. There were only two other ecclesiastical prince-electors in the Empire: the Electorate of Mainz and the Electorate of Trier. The archbishop-elector of Cologne was also arch-chancellor of Italy (one of the three component titular kingdoms of the Holy Roman Empire, the other two being Germany and Burgundy) and, as such, ranked second among all ecclesiastical and secular princes of the Empire, after the archbishop-elector of Mainz, and before that of Trier.

The capital of the electorate was Cologne. Conflicts with the citizens of Cologne caused the elector to move to Bonn. The Free Imperial City of Cologne was recognized after 1475, thus removing it from even the nominal secular authority of the elector. Cologne and Bonn were occupied by France in 1794. The right bank territories of the electorate were secularized in 1803 during the German mediatization.

A brothel, strumpet house, bordello, bawdy house, ranch, house of ill repute, house of ill fame, or whorehouse is a place where people engage in sexual activity with prostitutes. For legal or cultural reasons, establishments often describe themselves as massage parlors, bars, strip clubs, body rub parlours, studios, or by some other description. Sex work in a brothel is considered safer than street prostitution.

The Latin word insula (lit. 'island'; pl.: insulae) was used in Roman cities to mean either a city block in a city plan (i.e. a building area surrounded by four streets) or later a type of apartment building that occupied such a city block specifically in Rome and nearby Ostia. The latter type of Insulae were known to be prone to fire and rife with disease.

A standard Roman city plan was based on a grid of orthogonal (laid out on right angles) streets. It was founded on ancient Greek city models, described by Hippodamus. It was used especially when new cities were established, e.g. in Roman coloniae.

North Rhine-Westphalia or North-Rhine/Westphalia, commonly shortened to NRW, is a state (Land) in Western Germany. With more than 18 million inhabitants, it is the most populous state in Germany. Apart from the city-states (Berlin, Hamburg and Bremen), it is also the most densely populated state in Germany. Covering an area of 34,084 km (13,160 sq mi), it is the fourth-largest German state by size.

North Rhine-Westphalia features 30 of the 81 German municipalities with over 100,000 inhabitants, including Cologne (over 1 million), the state capital Düsseldorf (630,000), Dortmund and Essen (about 590,000 inhabitants each) and other cities predominantly located in the Rhine-Ruhr metropolitan area, the largest urban area in Germany and the fourth-largest on the European continent. The location of the Rhine-Ruhr at the heart of the European Blue Banana makes it well connected to other major European cities and metropolitan areas like the Randstad, the Flemish Diamond and the Frankfurt Rhine-Main Region.

The Bergisches Land (German pronunciation: [ˈbɛʁɡɪʃəs ˈlant], lit. 'Bergian Land') is a low mountain range in the state of North Rhine-Westphalia, Germany, east of the Rhine and south of the Ruhr. The landscape is shaped by forests, meadows, rivers and creeks and contains over twenty artificial lakes. Wuppertal is the biggest town, while the southern part has economic and socio-cultural ties to Cologne. Wuppertal and the neighbouring cities of Remscheid and Solingen form the Bergisches Städtedreieck (Berg City Triangle).