Spain
A dive area in the bay of Las Coloradas, Playa Blanca, within Lanzarote's UNESCO Biosphere Reserve, built around Museo Atlántico, Europe's first underwater sculpture museum and artificial reef by Jason deCaires Taylor.
Lanzarote was declared a UNESCO Biosphere Reserve in 1993. Museo Atlántico opened from 2016 in the Bay of Las Coloradas, submerged at 12-15 m, roughly 300 m offshore. Its roughly ten installations cover about 2,500 m2 of seabed and function as an artificial reef, with operators reporting over 200% growth in marine-life diversity since installation. Source: Wikipedia (Lanzarote), underwatersculpture.com, es.wikipedia.org (Museo Atlántico).