Vuosaari is the easternmost district in Helsinki, and it also covers the largest area. It is bordered to the north by Vantaa and to the east by Sipoo. The southern part of Vuosaari comprises three large peninsulas – Ramsinniemi, Kallahdenniemi and Uutela – as well as numerous islands. The nature in Vuosaari is very diverse, and there are several nature reserves, including Kallahdenharju and Porvarinlahti. Vuosaari has been developed in phases in the 1960s, 1980s and 2000s. As of 2013 the district had approximately 39,000 residents.