Castell Helen.
Gogarth is quite an intimidating place. However, Castell Helen is a welcoming sort of cliff. Although there are hard routes, there are several excellent VS's and a HVS.
Access to the cliff is via a short downhill walk from one of several nearby car parks. The base of the cliff can be gained by abseiling from below the RSPB Ellis Tower. If you have 50 metre ropes, you will need to do two abseils. The first abseil leads to a large ledge about half way down the cliff. From here another abseil leads to a platform at the base of the cliff. If you can't access the platform because the tide is too high there are several recesses near the bottom where you can belay.
At low tide you need to watch out if there is a swell. I once abseiled onto the platform with Steve Ralph aka "Jungle". Assuring him it was quite safe, I set off up something. When I got near to the half way ledge there was some muffled shouting and gurgling from below. I looked down to see Steve almost completely submerged by an unexpected wave. Luckily he was tied on to the base, so he didn't get washed off, pulling me off in the process.
The grooves either side of the halfway platform are taken by Pel and Rap, both of which are excellent climbs. The wall to the left is taken by Blanco. This is supposed to be HVS 5a. have done the route several times, by different variations and never found it 5a. If you tackle the overhang direct and ignore all holds to the side, I suppose it might be.
Once you reach the top it's less than five minutes walk to the cafe, where you can have a large slice of chocolate cake, before abseiling down to do another route.
There are excellent views of Red Wall - not that hard, but you wouldn't want to fall off as the holds are all portable. You can also look towards South Stack lighthouse and the incredible folded rock of Mousetrap.