The backwaters in Kerala were formed by waves and rivers creating low islands across river mouths. They consist of a network of lakes and canals fed by 38 rivers, extending along half of Kerala. Major lakes include Vembanadu, Ashtamudi, Punnamada, and Valiyaparamba. Houseboats are a prominent tourist attraction, allowing visitors to cruise along various routes. Famous boat races like the Nehru Trophy Race also take place on the backwaters. Ferry services connect locations along the backwaters.