Cacheu is a region in western Guinea-Bissau, on the border with Senegal. It has an area of 5,175 km² and a population estimated in 2004 at 16…Cacheu is a region in western Guinea-Bissau, on the border with Senegal. It has an area of 5,175 km² and a population estimated in 2004 at 164,676. Its capital is Cacheu. There has not been any local administration since the civil war of 1998-99 and all the social services are done by organs of civil society and other government agencies. It is a coastal region covered with Mangrove swamps, rain forest and tangled forest and receives an annual rainfall of more than 1,000 mm