English: El Castillo (The Castle). This is the city's (Tulum) most imposing building and its most important. The structure has two small rooms in its upper part where the principal religious ceremonies were held. The facade was decorated with sculptures. The upper temple was built on top of another building, which can still be seen from either side of the stairway. At ground level are two other small temples where offerings were deposited. El Castillo was dedicated to the Mayan god Kukulkan and is located on the site's highest point. In addition to its function as a temple, El Castillo may also have been used as a lighthouse or a kind of beacon.