Husband and I wanted to climb Avalanche Wall on Lliwedd. We are experienced multipitch trad climbers, had the correct equipment and the climb was well within our ability. It was a sunny day with plenty of daylight hours. We used the Rockfax guidebook to plan the day, but chose to take photos of the route and topo on our phones, instead of taking the book, to save weight. We were aware the crag was notoriously difficult to navigate. Upon approaching the crag, we realised the photo topo in the guide was taken from a different angle, as if you were below Crib Gogh, and not from the access path. The photo only showed half of the cliff as well. This made it very difficult to correctly identify which route was Avalanche Wall. We were persuaded by the sight of abandoned climbing ropes dangling down, plus a wrong assumption that the classic rock route would ascend the highest part of the cliff. We began climbing, and for the first 4 pitches the route description kind of matched what we were climbing. We also found old tat, which suggested we were on a route. In hindsight, there were errors but we 'made it fit'. It wasn't until the fifth pitch that the route became more grass than rock, very loose, with poor protection, that we realised we were way off route. We debated which direction to take, in the hope of regaining Avalanche Wall, but without knowing exactly where we were we decided this could get us into more trouble. We thought about abseiling off but were nervous about finding suitable abseil points below us - we were too high for a single ab. We now understood why there were abandoned ropes! We continued upwards, always choosing the easiest line, and topped out safely. We consider ourselves very lucky that we did not climb into more difficult territory and that neither of us slipped or a broke a hold. Once we reached the top of the cliff we looked for the iconic last pitch of Avalanche Wall. It was approximately 500m to our left!