11-12 Hanover Square is an office building in Mayfair, London W1. This marquee 8-storey development containing over 4,000sqm of office space was designed by Campbell Architects for Clients Aviva Investors pays homage to the refined architecture of Hanover Square, whilst presenting a more contemporary and articulate face to Oxford Street. The building features three levels of retail space, a high-quality reception, Portland stone walls and a roof garden. The nearest underground station is Oxford Circus.