The Baths of Titus have long been destroyed. They stood over part of the remains of Nero’s Golden House, itself filled with frescos.
A volume published in 1786 and now online, Ponce, Description des bains de Titus, here, contains a general view of the Baths, as they then stood, together with the entrance to the underground areas; plus two maps.
First the overview, including one of the massive exedras:
Next, a map of the underground areas, indicating the foundations of the exedras.
Finally a map of the overground area, with some elevations. I wonder, from the notes on it, how much of this was still standing in 1786, tho. I’m guessing this is merely a reconstruction from Piranesi, etc.
Update: Ste. Trombetti writes to say that in fact Ponce is a pixel-for-pixel reprint of Ludovico Mirri’s Vestigia delle terme di Tito e loro interne pitture, 1776, accessible at the Heidelberg Digital library here. (And, pleasingly, with a nice big “Download” button on it!)
Old maps of Rome can contain very useful information. At this site is the 1748 reproduction of the 1551 Bufalini map of Rome. The original is here, but for some strange reason is upside down and nearly unreadable. (Both sites have annoyingly provided us with a “viewer” rather than a download of the whole map).
Let’s look at one or two locations. The first is to look at St Peter’s:
The “Templum S. Petri” has the modern plan at the western end, but the Old Constantinian basilica at the East, leading into the atrium, then down some steps and into the “Forum S. Petri”. The Palace of the Pontiff faces into that piazza, which can be entered from the north through the wall that runs east to Castell S. Angelo. The same entrance in the wall into St. Peter’s square is used by modern visitors, coming from the metro station.
A circle at the bottom of the “new” portion indicates the location of the Vatican rotunda, a 3rd century tomb converted into a chapel and only demolished a couple of centuries later. To the right of it is a speck, which is the Vatican obelisk that now stands in St Peter’s square but then stood where it had stood for centuries, on the spina of the vanished Circus of Gaius and Nero.
There are various renaissance depictions of all these monuments online, and elsewhere on this site – click on the link for “Old St Peters” at the end of the post – but a map is invaluable.
Next let’s look at the area to the south of the Colosseum:
The Colosseum is next to the Palatine hill; but note the little shaded rectangle to the left of “Septizonium Severi” at lower centre. That is the location of the remains of the Septizonium, the monumental arcade-entrance to the Palatine, built as a facade by Septimus Severus and demolished only a few years later than the map. And to the left of the Colosseum is the dot marking the fountain, the Meta Sudans, which survived until Mussolini demolished it in the 1930’s.
Off to the right of the Colosseum, and beyond the church of S. Clemente, are the immense ruins of the Baths of Titus (Thermae Titi):
Let’s now wander off to the Quirinal Hill, up and left.
Somewhere in those streets is the modern Trevi Fountain. But in the centre is the now vanished remains of the Templum Solis Aureliani – Aurelian’s Temple of the Sun. Below it and to the right are the Baths of Constantine, the last major bath complex of imperial Rome.
I hope you have enjoyed your ramble around a vanished Rome.