Squares have long been a feature of London and come in numerous identifiable forms. The landscaping spectrum of squares stretches from those with more hardscape, constituting town squares (also known as city squares)—to those with communal gardens, for which London is a major international exponent, known as garden squares. London's largest privately owned square is Vincent Square, in Westminster, which comprises 13 acres.
A few in the capital of the United Kingdom, such as Trafalgar Square, began as public open spaces in the same way as other city squares worldwide, typically a plaza, piazza and a platz in Spain, Italy and Germany. Most, however, began as garden squares i.e. private communal gardens for the inhabitants of surrounding houses. All types of the space are more prevalent in parts of London with high (urban) density. Some of these gardens are now open to the public, while others, for example around Notting Hill, are railed (a form of fencing) and private.