Baths of Diocletian

The Baths of Diocletian were the largest imperial baths in ancient Rome, constructed by order of Emperor Diocletian at the end of the 3rd century and into the early 4th century AD. The complex originally included vast bathing halls, exercise areas and auxiliary rooms, covering a substantial area of the city.

Key surviving elements have been repurposed over centuries and now accommodate the Basilica of Santa Maria degli Angeli e dei Martiri and sections of the Museo Nazionale Romano, where visitors can see sculptures, inscriptions and architectural fragments from the baths. The layout includes traces of the frigidarium, caldarium and large vaulted halls, and the surviving scale of the complex gives a clear sense of its monumental size. Interpretation at the site explains bathing routines and the engineering behind heating and water supply.

Construction began under Diocletian in the late 3rd century AD and the baths were completed in the early 4th century as one of the final great imperial building programmes in Rome. Over the medieval and modern periods large parts of the structure were adapted for new uses, quarried for stone, or incorporated into Christian and civic buildings, preserving significant fragments for later study.

The complex lies in central Rome, northeast of the Capitoline Hill and adjacent to Termini railway station, making it readily accessible from major transport hubs.

• Scale and later reuse: The baths were the largest thermal complex in ancient Rome and could accommodate thousands of bathers; significant portions are integrated into later buildings and a national museum.
• Location and access: The site is adjacent to Rome's Termini station, making it one of the more accessible large Roman bath complexes for visitors to the city.

What to See #

• Santa Maria degli Angeli e dei Martiri (church): The Basilica of Santa Maria degli Angeli e dei Martiri, a church inserted into the repurposed frigidarium of the baths, designed by Michelangelo for the 16th-century church layout.
• Museo Nazionale Romano (exhibits): The Museo Nazionale Romano section housed in parts of the complex, exhibiting Roman sculpture, inscriptions and artefacts recovered from the baths and nearby sites.