Trevarno Mill

This is a watermill dating to the early 19th century, with extensions and alterations made around the middle of the 19th century and again in the late 19th or early 20th century. The mill is constructed from shale rubble with dressed granite quoins, jambstones, sills and lintels, and has slate sills to the original section. It features a hipped roof covered in asbestos slate, with a brick chimney stump positioned centrally on the front wall.

Originally, the mill was a square building, possibly with a pyramidal roof, two bays wide, built into the bank. It had an entrance in the middle of the front and included a loading doorway to the first floor, level with the bank. A large overshot waterwheel at the rear powered three pairs of millstones. In the mid-19th century, a granary or meal store, matching the original building in depth and almost as wide, was added to the right-hand side, with a large doorway in the middle of the right-hand end wall and two first-floor loading doorways. This granary was subsequently refloored to create three floors within the original mill space.

The south front presents a four-bay facade, symmetrical with a two-bay front for the original mill, centered on a doorway, and a two-bay front for the granary addition to the right, featuring a doorway on its left-hand side. Above the original mill’s doorway is inscribed "MANOR MILL R.PATTEN". The rear of the original mill has two first-floor window openings, and a largely complete 19th-century waterwheel with wooden spokes and iron rims. The rear of the granary mirrors the front, except that the original ground-floor window opening has been converted into a doorway.

The interior retains old floors and a later roof structure, alongside original wooden hursts supporting complete 19th-century machinery, including three pairs of millstones. One millstone is complete with its wooden housing, and one has its top stone detached.