Peña de Arias Montano Nature · Alájar, Sierra de Huelva, Huelva Rock outcrop with panoramic views over the south of the province, with a network of caves — including the one known as Palacio Oscuro — and a 6th-century early Christian baptismal font; the humanist Benito Arias Montano retired here after working on the Polyglot Bible and the Council of Trent. siglo VI (pila bautismal) Photo: PePeEfe (CC BY-SA 3.0) What to see and do in Alájar