The church of San Pietro di Valdottavo was built in a dominant location in Borgo a Mozzano. The impressive building is an interesting example of the techniques usually employed in urban centres being put to use in a rural area. The similarities with the church of Sant'Alessandro Maggiore in Lucca testify to the presence of artisans working indiscriminately in cities and in rural areas over the course of the 12th century.
The church is built on a Latin-cross plan with three naves and a semi-circular apse. The inside is illuminated by two series of single windows that open up along the naves and is decorated by an extraordinary series of architectural capitals.
In centuries following its construction, the church underwent a series of restructurings to fit with new liturgical demands and baroque sensibilities; as such, a transept, divided into small aisles by two pillars, was added to the north wall and long windows replaced the single windows. In a more recent times, a new, rectangular-plan apse that reached the height of the central nave was built.