These fourteen Corinthian marble columns (2.6m in diameter and 17m high) in the centre of an empty esplanade, are all that remains of what was once one of the largest temples in the Greek world. Begun between 560 and 510 BC, work on the temple was only completed in 132 under the Emperor Hadrian. The building originally comprised 104 columns arranged in three rows which formed a rectangle measuring 108m by 41m on the façade. Travellers have been impressed by the fallen majesty of this monument for centuries.