Citadel Aiud, Medieval fortress church in Aiud, Romania.

Citadel Aiud is a fortress church in the center of Aiud, Romania, surrounded by thick stone walls and several towers. Religious buildings stand inside the fortified perimeter, forming a compact historic complex in the middle of the town.

Archaeology shows a 3rd-century Daco-Roman settlement and an earthwork on this spot. The first fortress phase dates to the 14th century, when a fortified church stood here; local Saxon tradition placing it before the Mongol invasion of 1241 is unconfirmed. The walls and nine guild towers took their present form in the 16th–17th centuries.

The site shows how a medieval town community brought together worship and defense within one shared space. Walking through it today, visitors can still see how the church and the towers stand side by side, each serving a different but equally necessary purpose.

The citadel is located in central Aiud and is easy to reach on foot from most parts of town. Walking around the full perimeter gives a good sense of the scale of the walls and towers before entering.

The nine towers carry the names of the guilds that maintained them, such as the Butchers', Cobblers' and Coopers' towers. The Coopers' tower bears the guild emblem and the year of its last repair, 1744, cut into the stone. Guild officers chosen from these trades also served as the citadel's military commanders.