West London is generally considered to be the largest commercial district north of the River Thames, and is defined as an international centre of business and commerce by the City of London. It contains some of the most desirable and affluent neighborhoods in the city such as Knightsbriddge, Chelsea, kensington and Ladbroke Grove, as well as up and coming areas like Acton and Brentford, which have seen plenty of regeneration in recent years and an increase in property value in these areas. Historically significant buildings in the immediate area include Westminster Abbey and the Palace of Westminster, and there are many stately homes and gardens open to the public throughout west London such as Osterley, Gunnersbury and Boston Manor. The official boroughs of West London are Harrow, Brent, Ealing, Hounslow, Richmond Upon Thames and Hillingdon. West London has a surprisingly large amount of open green space owing to its royal parks considered to be areas of conservation and natural beauty. Places to see wildlife include Bushy Park and Richmond, where deer roam freely, and Holland Park with its resident peacocks. There is also the London Wetland Centre in Barnes, and Ruislip Lido which has its own artificial beach.