was erected by Symmachus, A.D. 500, on the site of the Church of S.
Silvester, in the time of Constantine. The nave is formed by
twenty-four ancient columns, said to have come from Hadrian's Villa.
The Confession, beneath the high altar, leads to the more ancient
church formed out of part of the Baths of Hadrian. It was here that
the Councils of A.D. 352-356 were held, when the acts of the Council
of Nicæa were condemned and burned. The landscape frescoes in the
upper church are by the brothers Poussin.
_From here we can best visit (No. 10 up the lane, turn round to the
left)_