The Maritime Theater is one the iconic buildings of Villa Adriana, unique and unmistakable, the most photographed one. In practice it was a miniature villa within the large imperial Villa.

The entrance has a pronaos with a columned portico and a short corridor with two rectangular niches, just before the main door. 

Inside there is another circular portico with Ionic columns and a circular channel surrounding a miniature island at its center.

The circular channel was like a moat in medieval castles: it made the island inaccessible. In ancient times there were two small wooden swing bridges. 

The emperor could isolate himself completely, rotating the bridges on special tracks of which traces have been found. Now there is a modern masonry bridge (closed to the public).

The island housed a miniature villa, with all the traditional elements of the Roman domus. It had a central atrium surrounded by a curved columned portico with a fountain in the centre, onto which rooms for entertainmenti or rest opened.

The central room on the south side, opposite the entrance, was a Triclinium, flanked by two smaller rooms. On the east side, the cooler one, there was a double cubicle for sleeping, with alcoves for two beds and small single lavatories.

On the opposite west side, the warmest, there is a miniature thermal plant, with a heated room and a tub for cold baths, from which with a few steps it was possible to go down and possibly swim in the circular canal - hence the name Natatorium.

The floors were in opus sectile but the marbles have disappeared. The walls were frescoed or covered with precious marbles. Even today the light reflected from the water sparkles on the walls, as if by magic.

The marble decoration is particularly refined with an extraordinary frieze with animals and sea monsters which was found in the sixteenth century during the excavations of Cardinal Farnese. From it comes the name «Maritime Theater", created in the nineteenth century by the French architect Blondel.

The island was the most private and exclusive place of the Villa, the secret refuge where the emperor Hadrian could completely 'isolate' himself from the world, inside a very luxurious miniature villa, with all comforts.