Long Ya Men or Longyamen (simplified Chinese: 龙牙门; traditional Chinese: 龍牙門; pinyin: lóngyámén; Malay: Batu Berlayar) or Dragon's Teeth Gate, is the name that Chinese explorer Wang Dayuan recorded for Batu Belayar, a craggy granite outcrop that formerly stood at the gateway to Keppel Harbour in Singapore. In his description, "The strait runs between the two hills of the Temasek (Chinese: 單馬錫; pinyin: Dānmǎxī; Pe̍h-ōe-jī: Tan-má-sek or Chinese: 淡馬錫; pinyin: Dànmǎxī; Pe̍h-ōe-jī: Tām-má-sek) natives which looked like a dragon's teeth." From there, the name Long Ya Men or Dragon Teeth's Gate was born.
The rocky outcrop served as a navigational aid to ancient mariners sailing through the swift waters of the narrow channel, but was subsequently destroyed by the British in 1848 to widen the channel for larger vessels to sail through. In 2005, a symbolic replica was erected by the Singapore government near its original site to mark the role it played in Singapore's maritime history.