This fortress, punctuated with towers and crenellations stands in a rocky island covered with trees and cacti, in the middle of the Tagus in which it is reflected... It was erected in 1171 by Gualdim Pais, Master of the Order of Knights Templar on the site of a Roman castle, and its particularly romantic setting has lent itself to many legends. From the pier there is an attractive view over the entire castle and its setting. From the top of the keep there is a seductive panoramic view over the river and the riverbanks.