Singapore lies between Malaysia and Indonesia, with a total area of 693 sq km and a coastline of 193 km. It consists of one main island and several other surrounding islets. It is often described as a gently undulating central plateau that contains water catchments and natural reserves. There is a small cluster of hills at the centre, and mangrove swamps along the coast, especially in the northern and western regions. The highest point in Singapore is Bukit Timah (a hill), with a height of 166 m which is situated in the central region of the island. The mainland measures 47 km from east to west and 28 km from north to south.
Geographically, there are three major regions in Singapore. The central hilly region has heavy deposits of granite (Bukit Timah, Bukit Batok, Bukit Panjang and Bukit Mandai). The west and southwestern parts of the island consist of sedimentary rocks, which have formed narrow ridges (Mount Faber Ridge and Pasir Panjang Ridge). The eastern part of Singapore is largely flat and sandy (from Katong to Bedok and Changi). It is also a rain shadow region and as a result receives less rainfall than the western region. The narrow Singapore River meanders through the city, with the Central Business District near its mouth. It boasts of an impressive skyline with many high rise buildings and apartments. This area also houses the shopping hub (Orchard Road), parks and attractive squares.
Over the years Singapore’s landscape has changed due to urbanization. The hilly central region has been levelled, mangrove swamps have been drained and filled, and the islets have been enlarged to set up industrial estates. Three main water reservoirs and their catchment area is what is left of the rain-forests and occupies the central region of the city-state.
As the island lies within 15 meters of sea level, its climate is influenced by the sea and its geographical location. Singapore does not face the danger of earthquakes, volcanoes or typhoons. However, it does experience occasional flash floods in certain low lying regions when there is excessive rainfall.