Amieira do Tejo (Off the IP6) - A perfect square, flanked by four towers, is the design of this unique castle. No other Portuguese castle shares its design, and none rises from the banks of a river with equal majesty. The castle was edified in the 14th century by Álvaro Gonçalves Pereira, a knight-turned-monk and father of the legendary Nuno Álvares Pereira. Today, its particular and square-like design is unique. The well-preserved main tower offers several amply Gothic rooms, and the original cistern and parade square are well maintained. Amieira retains a bold view, and special setting that transcends the centuries.