The Tower of Hercules, originally known as the "Farum Brigantium", is an ancient Roman lighthouse located on a peninsula about 2.4 kilometers from the center of La Coruña, Galicia, in north-western Spain. The tower was probably erected in the late 1st or early 2nd century, during the reign of Emperor Trajan (98-117), to facilitate navigation along the rugged Galicia coastline, on a strategic point on the sea route linking the Mediterranean to northwest Europe. The tower stands on a 57 meter high rock, and rises a further 55 meters, of which 34 meters correspond to the Roman masonry and 21 meters to the restoration in the 18th century, when the tower was augmented with two octagonal forms. The original beacon used a wood-fired system located on the summit and opening on to the seaward façade. A spiral staircase weaved around the exterior leading to the top. The tower has been in constant use since the 2nd century and is considered to be the oldest existing lighthouse in the world.