Roseau (rōzōˈ) [key], town (1991 pop. 15,853) capital and chief port of Dominica, in the Windward Islands in the West Indies. Located on the SW coast of the island. Roseau is on the small Roseau River, with some of the highest mountains in the Lesser Antilles towering over it. It exports limes, lime juice, essential oils, tropical vegetables, and spices. Waterfalls, thermal springs, and scenic plateaus are nearby. Sites of interest include a Roman Catholic cathedral (1841) and botanic gardens (1891).