Minecraft wiki entry for Elevators, associated text: A temporary waterfall can be used to make a safe ride down from any height. If one places a water source close to, or at, the edge of a long fall the water stream needs to be left flowing for only a few seconds to be safe to ride down. One can use the empty bucket to pick the source back up and then immediately walk off the edge in the stream to be carried over the edge and then ride it safely down. This also makes a safe landing site even in lava, but be aware that as soon as one lands on the obsidian that one has to move counter to the flow or risk being carried to the edge of the stream into the lava.