This quite, ochre coloured church is located in a small piazza not far from the Palazzo Spada,Via Giulia and Ponte Sisto.
It was built in the early 17th century on the site of a small parish church and was named Most Holy Trinity of Pilgrims and dedicated to the pilgrims who travelled to Rome.
The architect was Martino Longhi the Elder and building began in 1587 but it wasn't until 1723 that the Baroque facade was completed by Francesco de Santis, the architect who designed the Spanish Steps. Bernardino Ludovisi created the statues of the Evangelists in the facade's niches.
The church has three chapels either side of the nave, the high altarpiece of the Holy Trinity (1625) is by Guido Reni.
In the second chapel on the right is Filippo Bigioli di Sanseverino's 'Vision of Our Lady to St Philip'.
In the first chapel on the left is an altarpiece by il Borgognone (1677) of the 'Madonna and Child with Saints'.
In the second chapel, left side is the Virgin and Saints by Cavaliere d'Arpino.
The third chapel on the left, decorated with frescoes also holds the altarpiece 'St Gregory Freeing the Souls from Purgatory' by Baldassare Croce.