Minecraft wiki entry for Tips_and_tricks, associated text: To ascend a cliff, an alternative to ladders or pillar jumping is to use a bucket of water to place water as high as possible, then swim to the top of the waterfall, put the water back into the bucket, and quickly place a new waterfall at an even higher point. By repeating this process, a player can reach the top of the cliff. If the waterfall is left there, it can be used to travel back and forth.