Ledesma still has most of the granite wall which historically has surrounded the town. A large part of what is still standingwas 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, deSan 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. These buildings were declared a Site of Cultural Interest in 1949.