Also known as The Gherkin , 30 St Mary Axe is one of the tallest structures in London. Designed by Norman Foster, its construction was finished in 2003. Most of the building is covered with thick glass panels, which enhances the use of natural light and temperature. The building; which has 41 floors, uses much less energy for its activities compared to similar structures. It received the Royal Institute of British Architects (RIBA) Stirling Prize in 2004.