Pedra Branca (formerly referred to by Malaysia as Pulau Batu Puteh and now as Batu Puteh) is an outlying island and also the easternmost point of Singapore. The name means "white rock" in Portuguese, and refers to whitish guano (bird droppings) deposited on the rock. The island consists of a small outcrop of granite rocks with an area of about 8,560 square metres (92,100 sq ft). During the low water spring tide it measures, at its longest, 137 metres (449 ft) and has an average width of 60 metres (200 ft). It is situated at 1° 19′ 48″ N and 104° 24′ 27″ E, where the Singapore Strait meets the South China Sea. There are two maritime features near Pedra Branca. Middle Rocks, under the sovereignty of Malaysia, consists of two clusters of small rocks about 250 metres (820 ft) apart situated 0.6 nautical miles (1.1 km; 0.7 mi) south of Pedra Branca. South Ledge, which is 2.2 nautical miles (4.1 km; 2.5 mi) to the south-south-west of Pedra Branca, is a rock formation visible only at low-tide.
Pedra Branca was known to sailors for centuries. It was originally within the territory of the Johor Sultanate which was founded in 1528, and remained under the new Sultanate of Johor under the British sphere of influence following the signing of the Anglo–Dutch Treaty of 1824 between the United Kingdom and the Netherlands. Between 1850 and 1851, the British built Horsburgh Lighthouse on the island without informing the Johor authorities of their decision to do so or seeking consent for its erection. From that time, the island was administered by the United Kingdom and its successor, Singapore. On 21 September 1953, the Acting State Secretary of Johor, responding to a query from the Colonial Secretary of Singapore about the status of the island, stated that "the Johore Government does not claim ownership of Pedra Branca".