Few museums in the Maremma capture the history of the territory like this museum.
As well as Etruscan artifacts, Sovana's museum displays the funeral bust taken from the Tomba Ildebranda (3rd-2nd century B.C), which is actually open to visitors and part of the Parco Archeologico Città del Tufo.
The museum also has a priceless collection of medieval ceramics from the 15th century Sienese school. It's also free.
You can find the Centro di Documentazione del Territorio Sovanese, as it is otherwise known, in Sovana's Palazzo Pretorio.