Craig yr Aderyn (Bird Rock)

Craig yr Aderyn, Bird Rock, rises to 258m on the south bank of the River Dysynni, and Wikipedia gives its grid reference as SH 647066. It stands about two miles from the sea, which is the point of it: the crag supports the only regular inland breeding colony of cormorants in Wales, around 1% of the British breeding population according to Extreme North Wales, alongside choughs, peregrines and barn owls. Those birds are why it is a Site of Special Scientific Interest, and the Eryri National Park Authority owns the ground. The summit carries an Iron Age hillfort in two phases, an upper enclosure of about 0.6 hectares and a later stone-walled one of about 1.6 hectares, excavated in 1874, 1921 and 1967, with Roman-period finds from the first dig.

There is no public transport to the start. We Travel Wales gives the nearest bus stop as Bryncrug, about four miles away, so this is a drive from Tywyn of around six miles in all, two to Bryncrug and four on up the Dysynni valley. A small lay-by beside the single-track road holds six or seven cars, and the route begins through the gate in front of it. A loose-stone farm track climbs for roughly 580 yards, then a natural grass path branches off to the right and passes the stone banks of the hillfort before the rocky final slope. A bench about halfway up makes a natural stop, and the path becomes less distinct near the top.

AllTrails puts the out-and-back at 1.6 miles (2.6km) with 206m of ascent, taking an hour to an hour and a half; Extreme North Wales allows two hours with stops. UKClimbing’s logbook records a restriction closing the eastern face from 1 March to 31 July for the nesting birds, which is the part of the year to keep clear of the cliffs. It suits families with children old enough to manage a steep grass slope and anyone who wants a hillfort and a view along the Dysynni valley for an hour or two of effort, but it does not suit visitors with limited mobility, since the climb is steep and the top is rocky, and young children need holding near the unfenced edges. For the mountain view without the climb, Cregennan Lakes is reached by car and needs almost no walking.