Santa Maria in Traspontina is a Carmelite church on the Via della Conciliazione, near Vatican City, dedicated to the Blessed Virgin Mary.
For reference, a plan of the church is available
here.
The first church, which had the same dedication, was built under Pope
Hadrian I (772-795). It was not in the same spot, but closer to Castel Sant'Angelo.
Pope
Alexander VI Borgia (1492-1503) demolished an ancient Roman pyramid on the same site (the
Meta Romuli, believed in the Middle Ages to be Romulus's tomb, and portrayed on the bronze doors to St Peter's Basilica) for the construction of the first church. That church was then demolished during the pontificate of
Pius IV Medici (1559-1565) to clear the line of fire for the cannons of the Castel Sant' Angelo.
Designs by
Giovanni Sallustio Peruzzi (with contributions by
Ottavio Mascherino and
Francesco Peparelli) for a replacement church were in place by 1566, though the papal artillery officers insisted that its dome be as low as possible to avoid a recurrence of the previous problem. This meant that the new church's dome was built without a supporting drum. The church was completed in 1668.
