The couple were married at Santo Stefano degli Abissini, an 8th-century church in Vatican City and held their reception at Castello Odescalchi, a 15th-century castle in nearby Bracciano – the same castle where Tom Cruise and Katie Holmes were married in 2006.
Rome "is the true city of romance, and to be able to wed in the Eternal City is all we could have asked for this occasion," the couple tell PEOPLE.
They described the wedding ceremony as "very traditional and romantic." A quartet, organist and soprano performed as Suvari, 31, walked down the aisle in a dress by alice + olivia designer Stacey Bendet with Claudia Ciuti shoes and Nova Diamonds earrings. Sestito, 25, a concert producer, designed the couple's white-gold wedding bands himself.
The floral arrangements and decor, both at the church and the castle, were done by Adriano Ceccoti.
At the reception, guests enjoyed risotto, raviolini and veal carré dishes. The couple's first dance was to an original dedication by Mario Reyes, a.k.a. the Gipsy Man, performing with members of the Gipsy Kings. The evening also featured a fireworks display.
Suvari said the newlyweds are now spending a few more days with friends and family in Rome before enjoying a honeymoon traveling around Italy. After that, she added, they're looking forward to "a happy, fruitful life together."