The first mention of the Oratory dedicated to the Holy Trinity and located in the high part of Arquà, dates back to 1181. Francesco Petrarca often came to this church to pray.
During the 14th century, the Oratory was enlarged and frescoed and in the year 1400 the apse was added. Inside, it is possible to admire the wooden altar of the 17th century and the magnificent altar piece by Palma il Giovane - the famous Mannerist artist - representing the Holy Trinity. The leather in front, depicting the Resurrection of Christ, dates back to the 17th century as well. Near the altar, there are the painted stone statue of S. Cristoforo. It is important to remark the presence of a valuable picture by Giovanni Battista Pellizzari - one of the most important artists of the 16th century in Veneto – representing the ordinance ceremony of a new Vicar.
One of the most precious works of art kept in the Oratory is the so-called Polittico di Sant’Agostino by Jacobello di Bonomo, painted in the second half of the 14th century.