The Dead Sea is over 430 metres below sea level and dropping about a metre per year.

Lake Baikal is the deepest freshwater lake in the world.

The city of Istanbul spans two continents — Europe and Asia.

There are mountains on Earth taller than Everest when measured from base to peak underwater.

Iceland sits directly on the Mid-Atlantic Ridge and is actually spreading by 2.5 cm per year as two tectonic plates diverge.

The city of Jericho is one of the oldest known walled cities.

More people live in Tokyo than in the entire country of Canada.

The London Underground is one of the oldest metro systems in the world.

There are places on Earth that have never been explored.