The Baths of Diocletian were begun in 298 AD on one of the highest parts of Rome, the Viminal, and seem to have been completed by 305 AD when Diocletian abdicated. The basic plan of the baths is heavily based on the earlier examples of the baths of Titus, Trajan and Caracalla (indeed, the ground plan is very similar to the latter and of almost the same dimensions.) As with other similar establishments, the baths consisted of a central building (the main bath house) or which large parts survive, gardens and running tracks, all surrounded by an enclosing wall which in itself contained libraries, shrines and other buildings. The baths owe their remarkable state of survival to the conversion of much of the central section into a Church. The interior of the church still contains four decorative columns from the original bath house. The shape of the outer wall can easily be traced even where it is long gone, as the curve of the Piazza della Repubblica follows the line of the huge exedra. The north wall still survives in part. The best way to explore the numerous remains and wonders of the baths is to wander the entire area. Visit the whole structure:

1. The National Museum occupies part with access from Piazza dei Cinquecento opposite the station. This will give you access to the rear wall and the eastern end of the main building.

2. From the Piazza della Repubblica, enter the church of S. Maria degli Angeli. Make sure to try and get to the sacristy which occupies other parts of the baths.

3. Continue around the other side to Via Parigi and find the so-called Octagonal Hall and ruins of the western end of the main building.

4. In the Piazza San Bernardo to the southwest is one corner tower of the outside wall later converted into a circular church.

5. The other corner tower is visible along the Via del Viminale.