Swallow Reef, also known as Malay: Pulau Layang-Layang; Vietnamese: Đá Hoa Lau; Mandarin Chinese: 燕子島; pinyin: Yànzi Dǎo; Celerio Reef (Filipino: Bahura ng Celerio), is an oceanic atoll of the Spratly Islands administered by Malaysia.

It is closed to tourists from November to January each year due to heavy monsoon rains, however, Malaysian Armed Forces personnel operate on the island year-long.

[7] In May 1983, eighteen PASKAL members built their first encampment, signifying the start of the Royal Malaysian Navy's presence.

At the time, the only infrastructure available was a helipad for personnel transfer, and the special forces had to camp under the open skies on the bare reef.

[7][8] By 1995, more buildings were added, including two air-conditioned accommodation blocks, an aircraft landing strip, two hangars, a radar station, an air traffic control tower, watchtowers and a jetty.

[8] On 5 March 2009, Abdullah Ahmad Badawi, the Malaysian Prime Minister of the time, visited the island.

The jetty is located inside the lagoon of the submerged atoll, and has access to the sea through a man-made path cleared of corals.

Several anti-ship and anti-aircraft guns are placed around the reef, and the personnel operate a Starburst air defence system to prevent low level attacks on the island.

[citation needed] Layang-Layang is a 3 star resort located on the island open from 28 February – 1 September.