(CNN) — "Going up that river was like traveling back to the earliest beginnings of the world ... an empty stream, a great silence, an impenetrable forest," wrote Joseph Conrad in classic novella "Heart of Darkness." He was speaking of a journey along the Congo River, but the same could be said for any great African lake or river. Even more than the deserts, mountains and great plains, the continent's waterways reflect the blend of wildness, beauty and serenity that initially draws people to Africa and keeps them coming back. "Water journeys in Africa are particularly alluring because rivers are communication channels and lifelines," says Guy Lankester of From Here 2 Tumbuktu , an adventure travel company that books trips on the Senegal and Niger rivers in West Africa. Here are 10 of Africa's most impressive water adventures: 1. Houseboating the Chobe River (Namibia and Botswana) Zambezi Queen offers safari...