The Rock of Gibraltar, English Language and, which stems from the Arabic Jabal Ṭāriq, "Tariq's Mountain"; originally called Calpe) is a monolithic limestone promontory located in the British overseas territory of Gibraltar, near the southwestern tip of Europe on the Iberian Peninsula. It is 426m high. The Rock is Crown property of the United Kingdom, and borders Spain. Most of the Rock's upper area is covered by a nature reserve, which is home to around 300 Barbary macaques. These macaques, as well as a labyrinthine network of tunnels, attract a large number of tourists each year.The Rock of Gibraltar was one of the Pillars of Hercules and was known to the Romans as Mons Calpe, the other pillar being Mons Abyla or Jebel Musa on the African side of the Strait. In ancient times, the two points marked the limit to the known world, a myth originally fostered by the Greeks and the Phoenicians.