Malaita island is inhabited by "salt water" people along the coast and "bush" people in the mountainous inland. In the past, the salt water people escaped the headhunting bush people by making artificial islands out of blocks of dead coral near the outer reef. Here, they built houses, planted palm trees and made a protected living. Since the introduction of Christianity, the tribal warfare has stopped and the salt water people have now moved back on the mangrove covered shore. Every time they needed more land, a slab of traditional man-made coral estate was added – a practice that continues to this day.