Two miles west of Holyhead, the sea vents its fury against the cliffs of South Stack, an important RSPB reserve – home to thousands of seabirds. A steep, serpentine flight of steps leads down to the suspension bridge that crosses over to the South Stack Lighthouse for tremendous cliff views. Numerous paths lead into the bracken-covered, hilly interior, climbing the 219m Holyhead Mountain (Mynydd Twr) and skirting Neolithic stone circles. South Stack Kitchen, an interpretive-centre-cum-cafe providing maps and information, is open all year.
Between May and June around 12,000 guillemots, 1200 razorbills and 15 loved-up puffin couples congregate on the cliffs here – and that's not to mention the choughs, fulmars, peregrine falcons and numerous other species that can be spotted throughout the year. For a sheltered view, head to Twr Ellin (Ellin's Tower; April to September), a birdwatcher magnet equipped with binoculars, telescopes and a TV with a live feed from cameras on the cliffs.
Caer y Twr, one of Wales' most impressive Iron Age sites, is found at the blustery summit of Holyhead Mountain, but if you're not up to a 45-minute hike, there are also remains of Neolithic round houses a short stroll along a path that's opposite the car park.