Villa Hadriana, near Tivoli, Italy. Western parts, the Hundred Chambers.

The Hadrian's Villa (Villa Adriana in Italian) is a large Roman archaeological complex at Tivoli, Italy. It is a property of the Republic of Italy, and directed and run by the Polo Museale del Lazio since December 2014.
The villa was constructed at Tibur (modern-day Tivoli) as a retreat from Rome for Roman Emperor Hadrian during the second and third decades of the 2nd century AD. Hadrian was said to dislike the palace on the Palatine Hill in Rome, leading to the construction of the retreat. During the later years of his reign, he actually governed the empire from the villa. A large court therefore lived there permanently. The postal service kept it in contact with Rome 29 km (18 mi) away.

The "Cento Camerelle" (or "The Hundred Chambers") is the name given to a series of rooms probably used for storing supplies and housing slaves. Located along the western side of the Pecile terrace, it consisted of four stories of rooms accessible from concrete stairs that led to wooden balconies. Estimates of the number of rooms, which were paved in opus signinum, vary between 125 and 200. The lowest level included a latrine paved in opus spicatum. It led to a service corridor leading all the way to the Vestibule and the adjacent baths.

more on https://en.wikipedia.org/wiki/Hadrian's_Villa , http://vwhl.clas.virginia.edu/villa/ and http://vwhl.clas.virginia.edu/villa/thehundredchambers.php

picture generously provided by Rudolf Kaufmann (2015)