Today’s feast day in the Latin Church is the Dedication of St. John Lateran. It’s the only “archbasilica” in Christianity as the chief and highest-ranking church in the world—the Mother Church.
Briefly, this area of Rome just inside the city walls was given to the Pope around the year 300 or so with a church on the site dedicated in 324. For a long time, the Pope lived at the Lateran and a number of councils were held here over the years.
It was–and still is—the Cathedral for the Diocese of Rome and for the Bishop of Rome, which is just another name for the Pope. St. Peter’s is just another church, but St. John Lateran is the Cathedral.
I’ve been able to visit a couple of times; here are a few pictures from April 2019, including the Baptistry adjacent.
Whenever we come to church, we must prepare our hearts to be as beautiful as we expect this church to be. Do you wish to find this basilica immaculately clean? Then do not soil your soul with the filth of sins. Do you wish this basilica to be full of light? God too wishes that your soul be not in darkness, but that the light of good works shine in us, so that he who dwells in the heavens will be glorified. Just as you enter this church building, so God wishes to enter into your soul, for he promised: I shall live in them, I shall walk through their hearts.St. Caesarius of Arles as found in the Office of Readings.