Berlin is the capital and largest city of Germany by both area and population. Its 3,769,495 (2019) The city is one of Germany's 16 federal states. It is surrounded by the state of Brandenburg, and contiguous with Potsdam, Brandenburg's capital. The two cities are at the center of the Berlin-Brandenburg capital region, which is, with about six million inhabitants and an area of more than 30,000 km², Germany's third-largest metropolitan region after the Rhine-Ruhr and Rhine-Main regions. Berlin straddles the banks of the River Spree, which flows into the River Havel (a tributary of the River Elbe) in the western borough of Spandau. Among the city's main topographical features are the many lakes in the western and southeastern boroughs formed by the Spree, Havel, and Dahme rivers (the largest of which is Lake Müggelsee). Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. About one-third of the city's area is composed of forests, parks, gardens, rivers, canals and lakes. The city lies in the Central German dialect area, the Berlin dialect being a variant of the Lusatian-New Marchian dialects. First documented in the 13th century and situated at the crossing of two important historic trade routes, Berlin became the capital of the Margraviate of Brandenburg (1417–1701), the Kingdom of Prussia (1701–1918), the German Empire (1871–1918), the Weimar Republic (1919–1933), and the Third Reich (1933–1945). Berlin in the 1920s was the third largest municipality in the world. After World War II and its subsequent occupation by the victorious countries, the city was divided; West Berlin became a de facto West German exclave, surrounded by the Berlin Wall (1961–1989) and East German territory. East Berlin was declared capital of East Germany, while Bonn became the West German capital. Following German reunification in 1990, Berlin once again became the capital of all of Germany. Berlin is a world city of culture, politics, media and science. Its economy is based on high-tech firms and the service sector, encompassing a diverse range of creative industries, research facilities, media corporations and convention venues. Berlin serves as a continental hub for air and rail traffic and has a highly complex public transportation network. The metropolis is a popular tourist destination. Significant industries also include IT, pharmaceuticals, biomedical engineering, clean tech, biotechnology, construction and electronics. Berlin is home to world-renowned universities such as the Humboldt Universität zu Berlin (HU Berlin), the Technische Universität Berlin (TU Berlin), the Freie Universität Berlin (Free University of Berlin), the Universität der Künste (University of the Arts, UdK) and the Berlin School of Economics and Law. The city has numerous orchestras, museums, and entertainment venues, and is host to many sporting events. Its Zoological Garden is the most visited zoo in Europe and one of the most popular worldwide. With the world's oldest large-scale movie studio complex, Berlin is an increasingly popular location for international film productions. The city is well known for its festivals, diverse architecture, nightlife, contemporary arts and a very high quality of living. Since the 2000s Berlin has seen the emergence of a cosmopolitan entrepreneurial scene.

London is the capital and largest city of England and the United Kingdom. Standing on the River Thames in the south-east of England, at the head of its estuary leading to the North Sea, London has been a major settlement for two millennia. Londinium was founded by the Romans. The City of London, London's ancient core − an area of just and colloquially known as the Square Mile − retains boundaries that follow closely its medieval limits. The City of Westminster is also an Inner London borough holding city status. Greater London is governed by the Mayor of London and the London Assembly. London is considered to be one of the world's most important global cities and has been termed the world's most powerful, most desirable, most influential, most visited, most expensive, innovative, sustainable, most investment friendly, and most popular for work city in the world. London exerts a considerable impact upon the arts, commerce, education, entertainment, fashion, finance, healthcare, media, professional services, research and development, tourism and transportation. London ranks 26 out of 300 major cities for economic performance. It is one of the largest financial centres and has either the fifth or sixth largest metropolitan area GDP. It is the most-visited city as measured by international arrivals and has the busiest city airport system as measured by passenger traffic. It is the leading investment destination, hosting more international retailers and ultra high-net-worth individuals than any other city. London's universities form the largest concentration of higher education institutes in Europe, and is home of world-class institutions such as Imperial College London in science, technology, engineering, and mathematics and the London School of Economics in economics, finance, and business. In 2012, London became the first city to have hosted three modern Summer Olympic Games. London has a diverse range of people and cultures, and more than 300 languages are spoken in the region. Its estimated mid-2018 municipal population (corresponding to Greater London) was 8,908,081, the most populous of any city in the European Union and accounting for 13.4% of the UK population. London's urban area is the second most populous in the EU, after Paris, with 9,787,426 inhabitants at the 2011 census. The population within the London commuter belt is the most populous in the EU with 14,040,163 inhabitants in 2016. London was the world's most populous city from 1831 to 1925. London contains four World Heritage Sites: the Tower of London; Kew Gardens; the site comprising the Palace of Westminster, Westminster Abbey, and St Margaret's Church; and the historic settlement in Greenwich where the Royal Observatory, Greenwich defines the Prime Meridian, 0° longitude, and Greenwich Mean Time. Other landmarks include Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge, Trafalgar Square and The Shard. London has numerous museums, galleries, libraries and sporting events. These include the British Museum, National Gallery, Natural History Museum, Tate Modern, British Library and West End theatres. The London Underground is the oldest underground railway network in the world.