sentences:  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.Since 1822, there were land reclamation works by British, who at that time controlled the island and the government of Singapore has continued to increase the size of the island after independence, which increased the area of the island from in the 1960s to today.