Timijiraque is a small black-sand beach on El Hierro's east coast, useful because it gives the island a swim stop close to Puerto de la Estaca without losing the volcanic feel. The cove is backed by dark cliffs and usually feels more local than resort-like.
Conditions matter here. The Atlantic can be rough, and the beach is better for a scenic pause or careful swim than for a guaranteed lazy day. It fits well into an east-coast drive, especially if you are arriving by ferry or linking the port with Valverde and the southern viewpoints.