The Palmeral of Elche, a landscape of groves of date palms, was formally laid out, with elaborate irrigation systems, at the time the Muslim city of Elche was erected, towards the end of the tenth century A.C., when much of the Iberian peninsula was Arab. The Palmeral is an oasis, a system for agrarian production in arid areas. It is also a unique example of Arab agricultural practices on the European continent. Cultivation of date palms in Elche is known at least since the Iberian times, dating around the fifth century B.C.

Źródło: World Heritage Convention
http://whc.unesco.org/en/list/930