Santa Maria di Loreto is a 16th century church in Rome, located just across the street from the Trajan's Column, near the giant Monument of Vittorio Emanuele II, dedicated to the transposed house of the Virgin Mary's Annunciation in Loreto.
For reference, a plan of the church is available
here.
An earlier church on the site was given to the Confraternita dei Fornari, the Guild of Bakers, in 1500 by
Pope Alexander VI. It was very small, and they had it demolished a few years later to use the site for a bigger church.
The building of S. Maria di Loreto took place over a 60 year span. It was originally designed by
Donato Bramante in 1507, but very little was built for many years. In 1534
Antonio da Sangallo the Younger completed the lower, cube-shaped part, which was covered by a temporary roof. The dome was designed in 1573 by
Jacopo del Duca, a scholar of Michelangelo. The elaborated lantern inspired many Baroque architects including Francesco Borromini.