The Selous Game Reserve is an UNESCO World Heritage Site and at 55,000 sq. km is twice the size of Switzerland and just 200 km south west by air of Dar es Salaam.  It is the largest protected wildlife sanctuary in Africa and is widely accredited as being the most pristine wilderness.

The Selous boasts Tanzania's largest population of Elephant as well as a large number of Lion, African Hunting Dog, Leopard, Buffalo and Hippo. Species commonly seen are Bushbucks, Red and Blue Duikers, Eland, Hartebeest, Hyena, Kipspringer, Impala, Giraffe, Oryx, Reedbuck, Waterbuck and Zebra.

The bird life in Selous is extensive and the 400 species recorded include the globally threatened Wattled Crane and the Corncrake.

Black Rhino have been close to extinction, but can occasionally be seen in the vicinity of The Retreat.

The topography of the Game Reserve varies from rolling savannah woodlands, grassland plains and rocky outcrops intersected by the wide Rufiji and Ruaha Rivers. The Hippo population at The Retreat is one of the biggest seen in the Selous and guests can enjoy observing their activities from the privacy of their tent and the main house.