Tower of el Reloj de Jaca Monument · Jaca, La Jacetania, Huesca The Clock Tower of Jaca, also known as the Prison Tower, is a Gothic civil building constructed in 1445 after the fire that devastated the city around 1440, as a provisional solution while the cathedral and its prison facilities were being rebuilt. It was promoted by Canon Jorge Lasieso and financed by the Lasala family. Rectangular in plan and very slender, with an entrance door under a round arch on its north face, it came to be used as the residence of the merino, the royal official in charge of collecting taxes in the city, for which reason it was also known as the Tower or Palace of the Merino. In 1599 the Concejo de Jaca bought it to install the clock and bell tower, and in 1602 turned it into the city's prison. Photo: ERGOGAR (CC BY-SA 4.0) What to see and do in Jaca