Amphitheater Buttress

There are two ways in which the crag can be approached, a long gradual walk or a shorter steeper walk. Your choice will probably depend on where you happen to be traveling from or staying, as the driving distance between the two starts is some 26km, over a mixture of main and minor roads.

The steep southern approach starts in the Cwm Ogwen side of the Carneddau. Parking is available at the Gwern Gof Isaf campsite (SH 685 603), which is located just off the main A5 road and therefore is easy to reach from places like Capel Curig and Bethesda. There is a small fee to pay for this privilege, which is done at the farmhouse on the site itself.

From the campsite, turn right and walk down the main road in an easterly direction. After some 300m you will come to the access track for the Ffynnon Llugwy Reservoir, which joins the A5 on its northern side (SH 687 602). If you have not done so already, cross the road and take track, which rises in a more or less continual and straight line up the hillside. After about 2.5km, the track ends and a smaller path heads of north around the eastern side of the reservoir (SH 695 623). Take this path, which rises gradually at first, later steepening significantly, before joining the other paths on Bwlch Eryl Farchog (SH 694 633). It's from here that you will get your first glimpse of Craig yr Ysfa, which is just to the north. From here descend steeply down a small path into Cwm Eigiau and traverse along the base of the crag until you reach the start of the route, which can be identified by it's position just left of the huge gully known as The Amphitheater, from which the Buttress takes its name.

The more gradual and longer route begins from a small parking area at the end of a minor road in Cwm Eigiau (SH 731 633). This road is accessed via the County road of the B5106 in Tal-y-Bont. This start is the quickest choice if you are traveling to Snowdonia via the A55. It is the less strenuous option and takes you through one of the less visited parts of the National Park.

Leave the carpark and walk along the track which leads in a south-westerly direction towards Llyn Eigiau. The lake was once dammed as a reservoir, but was the of a disaster when on 2nd November 1925 the dam burst. The water flowed down to Coedty Reservoir, also causing that to burst, and millions of gallons of water flowed down into the village of Dolgarrog, causing the loss of 17 lives. The ruins of the dam and the remains of the breach can still be seen today. The path follows the edge of the dam, which once passed Hafod-y-rhiw (SH 723 646) gradually becomes smaller, and in places, boggier.

Continue along the track, crossing the Afon Eigiau (SH 718 640), until you reach the ruins associated old quarry workings on the northern flank of Pen yr Helgi Du (SH 702 636). The crags of Craig yr Ysfa now rear up in front of you and can be approached directly over open ground. As previously mentioned, the start of the route can be identified by it's position just left of a huge gully.

Descent

The descent is initially the same regardless of the approach you took, as you will walk off down the Penywaun-wen ridge to Bwlch Eryl Farchog. If you approached from the south you may now return along the same path as you walked in on, while if you came from the north, you will now need to descend steeply down the northern side of the saddle into Cwm Eigiau and back towards the old quarry buildings that you passed on the way up.

An excellent book describing many of Snowdonia's classic routes - the perfect bridge between scrambling and rock climbing.