The hamlet of Sant’Ermo appeared for the first time in XI century and it remembered for the church of Saint Ermete in 1260. It was under the control of the Pisan Upezzinghi’s counts , the presence of prestigious residential villa is documented in an act of XVIII century. The hamlet in 1833 counted 540 rezidents.
At Sant’Ermo is possible to benefit a great view that in the south of it you can see the hilly sites of Lari–Usigliano-Crespina, in the background the plain of Era and the Pisan plain, Pontedera, Ponsacco, Cascina, Pisa with the monumental zone, in the background the mountains of Lucchesia, Mountain Serra (Mountain Pisano), Mountain Verruca.
The hamlet was of the community of Lari since 1927, it formed with Ceppato, Collemontanino and Parlascio the community of Casciana Terme. From 1st Jannuary 2014 it flow into the new community of Casciana Terme Lari.