Singapore is made up of 63 islands, including the main island, which is known as Singapore Island to most people, but is also known as Pulau Ujong. There are two man-made connections to Johor, Malaysia: the Johor–Singapore Causeway in the north, and the Tuas Second Link in the west. Jurong Island, Pulau Tekong, Pulau Ubin and Sentosa are the largest of Singapore's smaller islands. The highest natural point is Bukit Timah Hill at .