Sounds like Basilica of San Clemente[1][2]. One of the many many many "hidden" g...

		clan 5 days ago \| parent \| context \| favorite \| on: Four strange places to see London's Roman Wall Sounds like Basilica of San Clemente[1][2]. One of the many many many "hidden" gems of Rome. Highly recommend visiting it! Or you can go on a virtual tour[3] [1] https://www.basilicasanclemente.com/eng/ [2] https://maps.app.goo.gl/zpXpQuxQLUvE5TLA9 [3] https://www.basilicasanclemente.com/eng/a-virtual-tour/

Thanks! And this is the article I remember https://www.exurbe.com/the-shape-of-rome/