The Church of San Leopoldo in Follonica, commissioned by Grand Duke Leopold II, was begun in 1836, consecrated in 1838 and finished in 1841.
The Church is Neoclassical in style, with a Latin cross and a cast-iron pronaos, a unique trait that characterizes the furnishings inside the church as well.
The columns supporting the decorated entablature, balustrade, central arch and friezes by the sculptor Nencini depicting St. Leopold handing out goods to the poor are all in cast-iron.
The theme pays tribute to the reclamation work carried out by Leopold II in the Maremma. All the cast-iron pieces were made by the Fonderie Ilva, which Leopold modernized in 1834, active until 1960 in working and producing iron pieces for street furniture, like the fountain in Arcidosso and the decorated pillars that surround the cathedral in Florence.