Suriname is mostly rolling highlands covered by tropical rain forests. The relatively small population is concentrated along the flat coastal plain, where the use of dikes makes cultivation possible. The people are largely of South Asian or mixed African and European ancestry; there is a significant Indonesian minority. Dutch is the official language, although English, Sranan Tongo (a creole English), Hindi, Javanese, and Brazilian Portuguese are widely spoken. Hinduism, the Moravian and Roman Catholic churches, and Islam are the predominant faiths.