It is an old relic of a time gone by. It is not something you would go out of your way to see however. Use this as a place to pass by on a walk to other sites. It makes the walk around Perugia that little bit more historic.
In the past it was main entrance gate to get to the historical center, located in Via Cavour, these ancient arches once lined precisely the entrance to the city.
If you were to start your tour of this city from here almost surely appreciate this beautiful sightseeing, however Perugia is a city full of art with very finest attractions.