Behind the Sala Grande of the Biblioteca Marciana is this excellent but still relatively unknown museum, which re-opened in 1999 after major renovations. The itinerary here is a bit confusing, but the useful brochures in English, French and German will help.
The museum was founded in 1523, when Cardinal Domenico Grimani left the State his impressive collection of Greek and Roman sculpture. A set of colossal 4th-century AD marble toes in the first room is followed by an extensive Roman coin collection, with some massive pieces guaranteed to put holes in a toga pocket (if togas had had pockets).
Images by Ethan Doyle White, GNU Free Documentation License