John Ray investigates the devastating floods in Kenya's great lakes region, where swelling waters have swallowed schools, villages and whole forests. Geraint Vincent travels to Bulgaria to meet an architect fighting to save the greatest icon to the country's communist past, as it re-evaluates its relationship with Soviet-era monuments and statues. In the remote forests of Romania, Romilly Weeks is on the hunt to find Europe's largest wild mammal, the bison.