Horsetail Falls is a small seasonal waterfall that only appears in late winter and early spring. It flows over the east side of El Capitan, so as a backdrop it has one of the most impressive walls of granite in the entire park. Then – only for part of February, and only when the sky is clear – the very last sunrays of the day selectively linger on the falls, lighting it up with a golden glow that makes the water look like lava.