Environment: Costa Rica is bordered to the north by Nicaragua and to the east by Panama. It has both a Caribbean and a Pacific coast. A series of volcanic mountain chains runs from the Nicaraguan border in the north-west to the Panamanian border in the south-east, splitting the country in two. In the center of these ranges is a high-altitude plain, with coastal lowlands on either side. Over half the population lives on this plain, which has fertile volcanic soils. The Caribbean coast is 212km (131mi) long and is characterized by mangroves, swamps and sandy beaches. The Pacific coast is much more rugged and rocky, and, thanks to a number of gulfs and peninsulas, is a tortuous 1016km (630mi) long.