Marismas del Odiel (sector de Aljaraque) Nature · Aljaraque, Comarca Metropolitana de Huelva, Huelva Image of Aljaraque, not of the place itself. The municipality of Aljaraque borders the Marismas del Odiel Nature Reserve, declared a UNESCO Biosphere Reserve in 1983. 1983 Photo: Alejandro Pereira (CC BY 2.0) What to see and do in Aljaraque