Here’s a place I’ve never used in a book. I still can’t help drifting back there whenever I’m in Rome though.

Santa Maria degli Angeli (e dei Martiri, if we’re to give the place its full title) is nothing to look at from the outside, just a few hundred metres from the bustle of Termini station. But within, it’s truly remarkable, and has quite a story to tell.

The facade is, in fact, the former tepidarium or the Baths of Diocletian, a part ruin now one of the great Roman museums just around the corner. In the mid sixteenth century Michelangelo was commissioned to turn the wrecked tepidarium into a church.

What you see today isn’t quite what he envisaged. The interior was tarted up during the eighteenth century, painting over Michelangelo’s plain, vast interior with some rather ornate additions. But the size and space is still quite remarkable, a reminder of the grandeur of the original Roman building, something which Michelangelo was determined to preserve.

Certainly worth a visit, and there’s an intriguing meridian line built into the floor, on the orders of a pope who wanted to check the accuracy of the Gregorian calendar. It is accompanied by a sundial that ties into lots of fancy stuff about the solar noon, and a hole in the wall through which the sun shines at a certain point on the summer solstice. But that’s all getting a bit Dan Brown for me. I just love the place for its wonderful sense of peace and scale, in a bustling and largely unlovely part of Rome.