Aruba: the waves of the windward coast carve the northern cliffs into high, arched coral bridges and deep limestone grottoes. In-between, winding roads lead to rocky passes and hidden coves, while tropical birds call to their mates, and flash brilliant colours against the deep blue of the Caribbean sky. Trinidadian immigrants working at the former Lago Oil Refinery in San Nicolas introduced Carnival which has become highlight of the Aruban calendar.