Reserva Natural Integral de Mencáfete Nature · Frontera, El Hierro, Santa Cruz de Tenerife Image of Frontera, not of the place itself. An area of 463.9 hectares within the Parque Rural de Frontera, near Sabinosa, that preserves one of the last remnants of El Hierro's laurisilva and monteverde forest, with a high concentration of endangered endemic species. It holds the island's only permanent water spring. 463,9 hectáreas Photo: Amada44 (CC BY-SA 4.0) What to see and do in Frontera