The Rock of Gibraltar (Spanish and Llanito: El Peñón de Gibraltar, sometimes called by its original Latin name, Calpe,) is a monolithic limestone promontory located in the British overseas territory of Gibraltar, off the southwestern tip of Europe on the Iberian Peninsula. It is 426 m (1,398 ft) 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.