Identify.

Porta Marzia, Perugia, 2nd-1st cent. BCE, facade of an Etruscan gate, wall continued to be built upon/rebuilt over the centuries, true arch, inlaid sculptures looking down behind latus screens, could have been made to look like a temple, could just represent important buildings, middle figure probably Tinia (Jupiter), flanked by Caster and Pollux (likely them because there are horses next to them and they are often depicted with horses), inscription to Colona Vibia