London

London (/ˈlʌndən/ LUN-dən) is the capital and largest city of both England and the United Kingdom, with a population of 8,866,180 in 2022. The wider metropolitan area is the largest in Western Europe, with a population of 14.9 million. London stands on the River Thames in southeast England, at the head of a 50-mile (80 km) estuary down to the North Sea, and has been a major settlement for nearly 2,000 years. Its ancient core and financial centre, the City of London, was founded by the Romans as Londinium and has retained its medieval boundaries. The City of Westminster, to the west of the City of London, has been the centuries-long host of the national government and parliament. London grew rapidly in the 19th century, becoming the world's largest city at the time. Since the 19th century, the name "London" has referred to the metropolis around the City of London, historically split between the counties of Middlesex, Essex, Surrey, Kent, and Hertfordshire, which since 1965 has largely comprised the administrative area of Greater London, governed by 33 local authorities and the Greater London Authority.
As one of the world's major global cities, London exerts a strong influence on world art, entertainment, fashion, commerce, finance, education, healthcare, media, science, technology, tourism, transport, and communications. Despite a post-Brexit exodus of stock listings from the London Stock Exchange, London remains Europe's most economically powerful city and one of the world's major financial centres. It hosts Europe's largest concentration of higher education institutions, some of which are the highest-ranked academic institutions in the world: Imperial College London in natural and applied sciences, the London School of Economics in social sciences, and the comprehensive University College London. It is the most visited city in Europe and has the world's busiest city airport system. The London Underground is the world's oldest rapid transit system.
London's diverse cultures encompass over 300 languages. The 2023 population of Greater London of just under 10 million made it Europe's third-most populous city, accounting for 13.4% of the United Kingdom's population and over 16% of England's population. The Greater London Built-up Area is the fourth-most populous in Europe, with about 9.8 million inhabitants as of 2011. The London metropolitan area is the third-most populous in Europe, with about 14 million inhabitants as of 2016, making London a megacity.
Four World Heritage Sites are located in London: Kew Gardens; the Tower of London; the site featuring the Palace of Westminster, Church of St Margaret, and Westminster Abbey; and the historic settlement in Greenwich where the Royal Observatory 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, and Trafalgar Square. The city has the most museums, art galleries, libraries, and cultural venues in the UK, including the British Museum, National Gallery, Natural History Museum, Tate Modern, British Library, and numerous West End theatres. Important sporting events held in London include the FA Cup Final, the Wimbledon Tennis Championships, and the London Marathon. It became the first city to host three Summer Olympic Games upon hosting the 2012 Summer Olympics.
== World Heritage Sites ==
There are 4 World Heritage Sites in London.
=== Kew Gardens ===
Kew Gardens is a botanic garden in southwest London that houses the "largest and most diverse botanical and mycological collections in the world". Founded in 1840, from the exotic garden at Kew Park, its living collections include some of the 27,000 taxa curated by Royal Botanic Gardens, Kew, while the herbarium, one of the largest in the world, has over 8.5 million preserved plant and fungal specimens. The library contains more than 750,000 volumes, and the illustrations collection contains more than 175,000 prints and drawings of plants.
=== Tower of London ===
The Tower of London is one of the oldestfortresses in the world. The guards who protect the tower are called beefeaters, probably because they used to eat a lot of beef. It is a historic castle on the north bank of the River Thames in central 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) until 1952 (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 became 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 zenith of the castle's use as a prison was the 16th and 17th centuries, when many figures who had fallen into disgrace, such as Elizabeth I before she became queen, Sir Walter Raleigh, and Elizabeth Throckmorton, were held within its walls. This use has led to the phrase "sent to the Tower". Despite its enduring reputation as a place of torture and death, popularised by 16th-century religious propagandists and 19th-century writers, only seven people were executed within the Tower before the world wars of the 20th century. Executions were more commonly held on the notorious Tower Hill to the north of the castle, with 112 occurring there over a 400-year period. In the latter half of the 19th century, institutions such as the Royal Mint moved out of the castle to other locations, leaving many buildings empty. Anthony Salvin and John Taylor took the opportunity to restore the Tower to what was felt to be its medieval appearance, clearing out many of the vacant post-medieval structures.
In the First and Second World Wars, the Tower was again used as a prison and witnessed the executions of 12 men for espionage. After the Second World War, damage caused during the Blitz was repaired, and the castle reopened to the public. Today, the Tower of London is one of the country's most popular tourist attractions.
=== Royal Observatory ===
The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park in south east London, overlooking the River Thames to the north. It played a major role in the history of astronomy and navigation, and because the Prime Meridian passed through it, it gave its name to Greenwich Mean Time, the precursor to today's Coordinated Universal Time (UTC). The ROG has the IAU observatory code of 000, the first in the list. ROG, the National Maritime Museum, the Queen's House and the clipper ship Cutty Sark are collectively designated Royal Museums Greenwich.
The observatory was commissioned in 1675 by King Charles II, with the foundation stone being laid on 10 August. The old hilltop site of Greenwich Castle was chosen by Sir Christopher Wren, a former Savilian Professor of Astronomy; as Greenwich Park was a royal estate, no new land needed to be bought. At that time the king also created the position of Astronomer Royal, to serve as the director of the observatory and to "apply himself with the most exact care and diligence to the rectifying of the tables of the motions of the heavens, and the places of the fixed stars, so as to find out the so much desired longitude of places for the perfecting of the art of navigation." He appointed John Flamsteed as the first Astronomer Royal. The building was completed in the summer of 1676. The building was often called "Flamsteed House", in reference to its first occupant.
The scientific work of the observatory was relocated elsewhere in stages in the first half of the 20th century, and the Greenwich site is now maintained almost exclusively as a museum, although the AMAT telescope became operational for astronomical research in 2018.