Set high on the cliffs overlooking the ocean in the typically commanding fashion of a military building, this fort was constructed to protect the local population from enemies approaching by sea or those looking for a possible landing site at low tide.

Now a museum, visitors get a good understanding of the building’s history through articles, photographs and exhibits (some recently added) relating to its construction and military role within the context of the many other forts built to protect the Tagus Estuary.