Punta Jesús María is a narrow sandbar projecting half a kilometre into Lake Nicaragua on the western side of the island. It is the best sunset spot on Ometepe — you walk out into the lake on a strip of sand with water on either side and the silhouette of Concepción looming behind you. There is a simple restaurant at the entrance and a few hammocks; otherwise it is just you, the sand, and the lake.
The water is warm and shallow enough to wade. Bring a swimsuit if you want to cool off, and arrive an hour before sunset to walk out, swim, and find a good spot for the light show. Easy bike ride from Moyogalpa or any of the western hotels.