It's a church built in the fifth century, which according to old writings was built on the spot where Peter and Andrew once lived according to the Gospel of John. So no disciples ever went there (though perhaps under there at a lower level), but it's still an important find, though the significance is being argued over and it's too early to say much.
Quite a bit more information, lots of background history and some other views on the find here: Church of the Apostles found by Sea of Galilee, archaeologists claim