Honduras borders Nicaragua in the southeast, Guatemala in the west, and in the southwest with El Salvador. To the north lies the Caribbean sea and to the south the Pacific Ocean. The interior of the country comprises a central mountain system from east to west, interrupted by rivers flowing into both the Caribbean and Pacific. The southern lowlands form a plain along the Pacific coast. The Gulf of Fonseca in the southwest contains many islands with volcanic peaks. The large fertile valleys of the northern Caribbean lowlands are covered with banana plantations. There are however, large areas of land in Honduras unsuitable for cultivation. The majority of the population lives in the western part of the country, while the next-largest concentration of people is in the Cortés area which continues northwards from Lake Yojoa up towards the Caribbean.