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:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.