The church can be visited
San Giovanni a Porta Latina Church
The Church of San Giovanni a Porta Latina, a basilica in Rome, is dedicated to John the Evangelist. Founded in the late 4th century, it underwent several transformations, shaping its current appearance.
History+
The origins of the Church of San Giovanni a Porta Latina date back to the late 4th century. A first renovation took place in the 5th century, followed by another restoration around 720. In 1191, the church was again repaired and received its distinctive campanile. The columns of the portico, as well as the columns in the three-aisled nave of the interior, are of ancient origin.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://en.wikipedia.org/wiki/File:%C3%89glise_San_Giovanni_a_Porta_Latina2.JPG
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 41.8772, 12.5019