Ledesma still has most of the granite wall which historically has surrounded the town. A large part of what is still standing was built in times of Fernando II of Leon, in the 12th century, but in the 15th century several parts of it were rebuilt with well-carved masonry. Many stone mason marks can be seen among these stones. Out of the eight doors it once had, the only one that is still preserved is the one called Puerta de los Mártires, de San Nicolás or Caldereros (Martyrs’, San Nicolás or Boilermakers’ door). Formed by two camber arches, it is flanked on either side by two cylinder towers.
The bailey of this castle-fortress was built on the south-west end of the walled area between the 13th and 14th centuries. Set on an irregular trapezoidal plan, it has two doors: one on the north, which features the town’s coat of arms, and one on the south, flanked by two large towers.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.