Romania: Aiud Citadel
Aiud Citadel is another example of the medieval fortified town/church. This was dates back to 1250s, when a watchtower was built to protect against Mongol invasion of Europe. It’s a real medieval mini-fortress with the high defensive walls that have 9 towers. Inside the walls, the citadel has 16th century royal palace and two Protestant churches – one Calvinist from the 15th century and one Evangelical from the 18th century.