A very popular religion in Rome

Rome is the city of bell towers: catholic churches are simply countless. That's not a big surprise in the city of the Pope. But would you be able to guess which religion is classified at the second place in an all-time chart based on the number of places of worship?

Not any of the other Christian confessions. Nor Muslim religion or Buddhism.

It is Mithraism, an ancient oriental monotheistic religion which was extremely popular during III and IV century of the Christian Era all over the Roman Empire. Mithra was identified with the Sol Invictus - the Undefeated Sun - and it was by far the most adored divinity by legionnaires. As usual, the Wikipedia entry about Mithraism is a good place to start to know more about some topic. It is curious to note as Christian and Mithraic iconography influenced each other a lot: the halo of the saints, for example, comes from a Mithraic tradition. Again, Mithra was born on December 25th, the day when daylight starts to increase again after Winter's solstice. Does this date remind you anything?

But how many Mithraic temple were built in Rome?

Probably about 2,000.

Eight of them are identified with absolute certainty and can be visited in Rome more or less easily:

1. The Mithraeum of Chancellery;
2. The Mithraeum of Via Giovanni Lanza;
3. The Mithraeum of S. Stefano Rotondo;
4. The Mithraeum Barberini;
5. The Mithraeum of Circo Massimo;
6. The Mithraeum of Caracalla's Thermae;
7. The Mithraeum of S. Clemente;
8. The Mithraeum of S. Prisca.