Tenerife beach blackish sand Published August 11, 2019 at 5312 × 2988 in A beautiful hike of the Barranco del Infierno in Adeje, Tenerife Playa del Duque is considered a premium beach on Costa Adeje in southern Tenerife, and we’d have to agree! It wasn’t crowded, it was clean, and it was beautiful. The water was so refreshing from the searing heat of the sun!