Most people need a visa except citizens of Mali, Chad, Central African Republic and Nigeria, and it is very advisable to obtain it before arriving.
There are many types of visa: airport transit visa for airport transit; visitor visa for visiting friends and family in Cameroon; business visas for work-relating activity in Cameroon; tourist visa for tourism purposes; student visa for studying abroad and learning at the universities; employment visa for taking up work in Cameroon; and permanent residence visa, which is issued if you a marry a Cameroonian.
Once in Cameroon, there is no additional requirement to visit Southwest Province or Bakossiland. However, visitors are expected to carry their travel documents with them at all times.
For more information, please visit the Cameroon High Commission in London:
Cameroon High Commission
84 Holland Park
Telephone: +44  20877 270 771