Monks Bridge, also known as Crossag or the Monks' Bridge, is a narrow, double-arched packhorse bridge over the Silverburn river immediately beside Rushen Abbey in Ballasalla, its surface paved with quartz cobbles. It is traditionally attributed to the Cistercian monks of Rushen Abbey, said to have used it to reach abbey farmland to the north; sources differ on the exact date, with some placing its construction in the 12th century and others around 1350. It sits on the historic Royal Way between Castletown and Ramsey, a route that today forms part of the Millennium Way, and aside from occasional repairs is thought to survive much as the monks built it. It is regarded as one of the finest surviving examples of a medieval packhorse bridge in the British Isles.