Pulau Tekong With an area of 2,365 ha, Pulau Tekong is the largest of Singapore’s offshore islands. It is the only part of Singapore extensively made of metamorphic rock known as the ‘Sajahat formation’. The interior is hilly, rising to 53 m in one place. Land reclamation schemes have been proposed which would double the size of the island, although studies of the potential effects on currents, patterns of erosion, marine life and shipping in the Strait of Johor have yet to be completed. Pulau Tekong is designated for use exclusively by the military, and has a resident armed- services population of around 5,000. It is off- limits to civilian visitors.