A small Pantheon - The Rotonda - in the Tregasio district of Triuggio, in the province of Monza e Brianza, is one of the most important examples of neoclassical art. 

The Rotonda was built in 1842 by Countess Federica d'Adda, widow of the architect Cagnola and who married again to the architect Nava, who designed this Rotonda (perhaps inspired by the design of a parish church by Cagnola).

It was declared an Italian national monument in 1912. Dedicated to Saints Gervasius and Protasius like the adjacent basilica, the Rotonda is 15 metres tall with a circumference of 10.8 metres.

Raised above street level by a staircase, the facade of the Rotonda is formed of a small pronaos held up by six caryatids, representing prayer, the eucharist and fear.

Inside it has four frescoes attributed to Raffaele Casnedi depicting scenes from the Gospels: Sermon on the Mount, Healing the man blind from birth, Raising of the son of the widow of Nain and the Story of the Adulteress.