Tonga, the "Friendly Islands", is an archipelago in the South Pacific Ocean. The country is divided into three main island groups, or regions. Much further to the north are the rarely visited and difficult to reach islands of Niuafo’ou, Niuatoputapu, and Tafahi, collectively known as the “Niuas”. Niuafo’ou is known as “Tin Can Island” because passing ships dropped mail in tin cans.