Cameroon:
In April 1999, coastal villages were evacuated because the volcanic 4,020-metre Mt. Cameroon was erupting, and lava flow was endangering the villages.
Apart from that, Cameroon is one of those African countries that is neither totally safe to travel to nor terribly dangerous. The biggest risk is from armed robbery in the cities of Douala and Yaounde, and at the fledgling beach resorts near Kribi on the Atlantic.
Cameroon has an abysmal human rights record that includes the political police using torture. A small, but very wealthy champagne-drinking elite rules over the impoverished minority.
You can go with a group to the northern game parks, or wander around the country on your own. The paperwork and bureaucracy usually creates massive roadblocks for travellers, so be prepared to play the waiting game and have people pulling power trips on you. There are 230 ethnic groups in Cameroon, but French or English will get you by.
Books: The Innocent Anthropologist: Notes from a Mud Hut, by Nigel Barley