Russia and the United States are less than 4 km apart at their closest point.

The Amazon River discharges more water into the ocean than the next seven largest rivers combined.

The Sydney Harbour Bridge is one of the largest steel arch bridges.

The Suez Canal significantly reduced travel time between Europe and Asia.

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

The Great Rift Valley in Africa may eventually split the continent in two, forming a new ocean in millions of years.

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

Antarctica is technically a desert — it receives less precipitation than the Sahara.

The Earth's crust varies in thickness beneath continents and oceans.