If you're interested in finding out about past civilizations, check out Archaeological Museum. Study its unearthed relics and gain an insight into the rituals and cultures of people from long ago.
When you've finished at this Massa Marittima exhibition of human history, why not check out Lago dell'Accesa, Cathedral of Massa Marittima, and Organ Museum of Santa Cecilia? They're not very far from Archaeological Museum and also popular with travelers.