There may have been earlier castles at this site, but the Mombeltran castle we see today was built by Don Beltrán de la Cueva, the first Duke of Alburquerque. He placed his coat of arms and those of his successive spouses above the entrance gate. This makes us believe that the construction of the castle took place between 1462 and 1474. The castle was donated to Don Beltrán by King Enrique IV, in 1461. Because there's architectural similarity between this castle and Belmonte Castle and Manzanares el Real Castle its architect probably has been Juan Guas. Although Mombeltrán Castle has a military and defensive appearance there are also many details of luxury for a palatial residence. Also in the 16th century the castle was modified for even more comfort.
Basically the castle is a square of rubblework and granite ashlar masonry with circular towers in the corners. The largest of those towers was the keep which has a central column in its interior on which the floors rest. Around the castle there is a second enclosure which closely follows the outlines of the inner one. This enclosure is equipped with a barbican.
Mombeltrán Castle lies on a beautiful spot, in the mountains of the Sierra de Gredos.References:
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.