Santi Gregorio e Siro

It was constructed by the canons of San Giorgio in Alga, an island in the lagoon of Venice; the architects were Tibaldo Tibaldi (Tibaldo Cristoforo di Tibaldi) and Giovanni Antonio, both from Milan.

In 1676, it passed to the order of Clerics Regular ministering to the sick (Chierici Regolari Ministri degli Infermi).

The earthquake of 1780 damaged the church, and it was rebuilt by the architect Angelo Venturoli.

The simple exterior does not reflect the highly decorated interior, which has ceiling frescoes by Luigi Samoggia and Alessandro Guardassoni (1868), a main altarpiece is a St Gregory shows the bleeding Eucharist to the Heretic by Denys Calvaert (1581) and works by Camillo Procaccini.

The altar decoration is in marble called Formaginni di Sanremo.