The buildings are substantial and varied, constructed mainly in random rubble sandstone with brick quoins and brick window surrounds, their north-facing rooflines glazed to draw in light for the workers inside. A dry millrace still traces its original course behind terraces of mill workers' houses, dropping some seven metres into a now-infilled wheel-pit along the east wall of the powerhouse. Nine weaving sheds run in a row at the south-east end of the complex, the river passing directly along their outer wall. Where Dobcross looms once clattered, and where a dedicated team of so-called invisible menders worked alongside the tweed shop and carpenter's workshop, there are now modernised interiors, though iron columns and open-plan floors survive in places.

The site has older roots than the surviving buildings suggest. Martin O'Mahony purchased the mill in 1824 and converted what had previously been a cotton and flax mill to woollen production. The 1842 Ordnance Survey six-inch map already shows a woollen mill on the western end of the present complex. A fire destroyed much of it in 1869, but the O'Mahony family rebuilt quickly; a datestone on the north elevation of the spinning mill reads "Rebuilt O'Mahony & Brothers 1870", and further extensions followed in 1880. By the 1880s the operation employed around 800 people and ran 113 power looms, 9,000 spindles for woollen spinning, 2,000 for worsted, and 2,300 for twisting. A hosiery section was added to the ground floor of one of the larger structures in 1926. The mill closed in 1975, its machinery and furnishings removed, though part of the complex was later reopened as a commercial retail outlet. Across the river, an overgrown ruin with adjacent infilled cleaning ponds marks a further fragment of the industry that once defined this stretch of the Martin.