Massa Marittima's Fonti dell'Abbondanza (Sources of Abundance) had a strategic role for the city: they were the only springs within the city walls for water supply, also used as a storehouse for grain collection, in the upper part of the building constructed in the 15th century. What is striking is not their impressive structure, but rather the special decoration dating back to 1265, the year of construction and a rare testimony of 13th-century wall painting.
Indeed, on the large back wall is the famous and highly original fresco of the Tree of Fertility. The work is an allegory of abundance, a propitiatory hymn to life, depicting a large tree from which hang, like huge fruits, dozens of phalluses. The fruits appear to be contested by fluttering birds and numerous women at the foot of the tree on what appears to be a day of celebration.
Also of note is a large black eagle presented in heraldic form with outstretched wings, symbolizing the city's Ghibelline faith from the time of its construction. Recent restorations have unearthed a new fresco depicting a woman holding two beasts on a chain and warriors who appear to be protecting the burrow from which the water flowed, along with two incomplete animal figures.
At present, the spring basins are empty to best preserve the precious fresco, while the upstairs spaces are used for city events and exhibitions.