Located in Inner London, the City of Westminster sits on the north bank of the River Thames. It is bordered by the City of London to the east, the Royal Borough of Kensington and Chelsea to the west, the London Borough of Camden to the north, and the Thames to the south (facing Lambeth and Wandsworth).
Despite being a highly developed, densely populated urban environment, Westminster is globally famous for its magnificent Royal Parks. Nearly a quarter of the borough's area is dedicated to green space, including Hyde Park, Kensington Gardens (shared with Kensington), Green Park, St James's Park, and Regent's Park.
The area's physical geography was historically shaped by several lost rivers of London, most notably the Tyburn and the Westbourne, which once flowed through the area into the Thames. Today, these rivers have been directed into London's extensive subterranean sewer system, though their ancient valleys still subtly influence the street layouts and drainage patterns of the borough.