|in case you wanted a close-up|
If that’s not enough, there are Christ’s footprints, the pole on which Sebastian met his arrows, and other relics. The San Sebastiano catacombs, next to and under the church, were the first to be called catacombs (a word meaning underground cemetery, apparently derived from the Greek for "hollow"--Bill).
If you want more on the iconography of this popular saint, Catholic Online has a good bio, tho' needless to say it doesn't talk about him being a gay icon.
It’s hard to say anything on the via Appia is off the beaten track; that’s really a non sequitur. But, approaching San Sebastiano from via delle Sette Chiese as we did, one feels almost as a pilgrim might have. And, unless a busload of tourists has just arrived to descend into the catacombs, you’ll pretty much have San Sebastiano to yourself, a treat in Rome.