Palencia Cathedral was built from 1172 to 1504 stands over a low vaulted Visigothic crypt (the Crypt of San Antolín). It is a large Gothic building, popularly dubbed as 'The unknown beauty' because not as well known as other Spanish cathedrals, though, it is a valuable building which has in its interior a large number of works of art of great value.
Its more than 130 metres long, 42 metres high and 50 metres wide at the centre, making it one of the largest cathedrals in Spain and Europe.
Its exterior solid, simple and austere does not reflect the grandeur of its interior, with more than twenty chapels of great artistic and historical interest. The most recognizable on the outside, is the tower, slim but a little rough, considering your Gothic style. Recent studies and excavations show that it was a military tower, and after serving this function were added to their pinnacles and cattail as the sole decoration.
The Cathedral's museum contains a number of important works of art, including a retablo of twelve panels by Juan de Flandes, court painter to Queen Isabella I of Castile and El Greco's St. Sebastian' (1576–79).
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.