Bill travels to the small Greek island of Ikaria to see why the residents there are getting much older than elsewhere.

India is home to an estimated 2,500 endangered Bengali tigers. Bill ventures deep into the jungle to meet up with animal rights activists in an effort to save these creatures.

Bill travels to Israel to meet up with activists fighting to preserve the Dead Sea, as experts fear the falling water level will mean that the special ecosystem will dry out.

The city of Venice is in danger of sinking from the rising sea levels. Constant floodings are a big burden on the floating city, so Bill talks to the local experts.