evidence: Singapore is separated from Indonesia by the Singapore Strait and from Malaysia by the Straits of Johor. Singapore's main territory is a diamond-shaped island, although its territory includes surrounding smaller islands. The farthest outlying island is Pedra Branca. Of Singapore's dozens of smaller islands, Jurong Island, Pulau Tekong, Pulau Ubin and Sentosa are the larger ones. Most of Singapore is no more than 15 meters above sea level. The highest point of Singapore is Bukit Timah Hill, with a height of 165 m (538 ft) and made up of igneous rock, granite. Hills and valleys of sedimentary rock dominate the northwest, while the eastern region consists of sandy and flatter land. Singapore has no natural lakes, but reservoirs and water catchment areas have been constructed to store fresh water for Singapore's water supply. [...] There are more than 300 parks and 4 nature reserves in Singapore. There are also many trees planted, and almost fifty per cent of the country is covered by greenery. Because of this, Singapore is also commonly known as the 'Garden City'. Singapore claims an exclusive fishing zone within and beyond its territorial sea, as defined in treaties and practice. Its territorial sea: extends 3 nautical miles (5.6 km) beyond its coastline.