Bard's Leap Summit is a location high in the mountains. A big waterfall is cleary visible and when jumped off (the *diving area) you will land in a small pool like area, with salmon.
For best results, do in the middle of the night. (special appearance)
However, if you fast travel to the location and you have a horse, it's possible the horse will spawn above the waterfall and float in the air. See video below: