Rwanda is a small country in East Africa. Located between Tanzania, Kenya, Congo Kinshasa and Burundi. On the small surface you find many mountains since the country is split by the Rift Valley, and dominated by a mountain range that traverses the country from north to south.
Kigali the capital is not really worth a visit unless it is for arranging the rest of your trip - and if you want to be visiting the national parks in the west you probably need to pass by.
The three principal areas of interest are the Volcanoes national park, the place to see the last mountain gorillas of the planet, the Akagera national park and the region around Lake Kivu.

Akagera national park
Gisenyi
Kigali
Volcanoes national park