High Quality Content by WIKIPEDIA articles! The Sisters' Islands are two of the Southern Islands in Singapore and are located to the south of the main island of Singapore, off the Straits of Singapore. Big Sister's Island, about 39,000 square metres (9.6 acres) in area and also known as Pulau Subar Laut in Malay, faces the open sea, while Little Sister's Island, about 17,000 m² (4.2 acres) in area and also known as Pulau Subar Darat in Malay, faces the mainland. The two islands are separated by a narrow channel. Currents through this channel can be very dangerous to swimmers and divers. As is common for roads with English names, it has an informal Chinese name, hei yuen kai, meaning Theatre Street in reference to the Lai Chun Yuen Theatre then located at unit 36 and the centre of entertainment in the Kreta Ayer area.