Porta San Paolo stands right next to the famous Pyramid of Cestius in Rome. This impressive gate is part of the ancient Aurelian Walls, which once surrounded the city to defend it from invaders.
The gate takes its name from Saint Paul, as the Via Ostiense—a historic road that begins here—leads directly to the Basilica of St. Paul Outside the Walls, one of the four major papal basilicas in Rome. This strategic location has long served as a link between the city and important religious destinations beyond its ancient boundaries, welcoming travelers and pilgrims alike.
Source - https://en.wikipedia.org/wiki/Porta_San_Paolo