The spectral ruins of Tintern Abbey sit by the River Wye, the worn stone scabbed with lichen and mottled grey, purple, pink and gold. Founded in 1131 by the Cistercian order, this sprawling monastic complex is one of the most intact medieval abbeys in Britain, its soaring Gothic arches and ornate tracery a testament to Cistercian wealth and power.
The haunting ruins and their riverside setting have inspired poets and artists through the centuries, including William Wordsworth, who penned Lines Composed a Few Miles Above Tintern Abbey during a visit in 1798, and JMW Turner, who made many paintings and drawings of the ruins.
The huge abbey church was built between 1269 and 1301, and the stone shell remains surprisingly intact; the finest feature is tracery that once contained the magnificent west windows. Spreading to the north are the remains of the cloisters, the infirmary, the chapter house, the refectory, the latrines, and a complex system of drains and sewers.
The site is clearly visible from the road, but if you want to explore it properly you'll need at least two hours to do it justice. It's best visited towards the end of the day after the coach-tour crowds have dispersed.
There are plenty of options for riverside walks around Tintern. One of the best begins at the old railway bridge just upstream from the abbey, and leads up to the Devil's Pulpit, a limestone crag on the east side of the river with a spectacular view over the abbey (2.5 miles round trip).
Bus 69 stops here, en route between Chepstow (15 minutes) and Monmouth (30 minutes).