Mosteiro de Santa Maria da Vitoria is another royal monastery built as a symbol of victory over Spain similar to the one in Alcobaca, but these two monasteries are totally different in style as Alcobaca is pure gothic and Batalha is unique Manueline.
Batalha monastery is very beautiful with stone carving in Manueline style and one of the best after the Monastery in Belem. The Royal Cloister's arches are one of the prettiest I ever seen, but the real jewel is the famous "Capelas Imperfeitas" which is the royal mausoleum which reminded me to India's amazing stone carving! Seeing Batalha is a great joy to see the exceptional work of art and one of my favorite places in Portugal.
For historical interest, this monastery is the resting place of Prince Henry, the navigator who played a major support for discovery age. His tomb is in the 'Capela do Fundador' room right next to main entrance.
Batalha monastery also has the tomb of unknown soldiers from WWI so this place is very important for Portuguese army and you can see some ceremonial guards walk around the area. So please show some respect when seeing this place.