Bali is a densely populated island. Most of the population live in closely packed villages of 2,000 to 4,000 people on the fertile southern slopes of the island, along the ridges that carry the irrigation ditches. On these slopes it is usually only a fifteen minute walk from one village to another through open rice fields. On the northern coastal strip, the villages are spread along the Java sea. Traditionally, the social organization of the island was based on the village, with each village being completely self-sufficient, providing all the needs and functions from birth through cremation. Recently, as in all industrializing countries, the cities and tourists centers are absorbing a portion of the population from the countryside and centralizing, to some extent, the flow of goods and services. The social organization of the villages is one of the most unique aspects of this enchanting island. The village is very much a communal unit, almost an extended family. The layout of a Balinese village and life of its members are closely tied to religion and the religious life of the people. The main community organization is the Banjar, which plans all ceremonies, including marriages and cremations, as well as mediates disputes that may arise within the community. Most villages have at least on Banjar, which have an average membership of 50 to 100 families. Each Banjar has a central meeting place, the Bale Banjar.