1) The Great Rift Valley is a geological feature that stretches over 6,000 kilometers (3,700 miles) from Lebanon to Mozambique. It is known for its diverse landscapes, including deep lakes, volcanic mountains, and fertile valleys, and is considered a significant site for the study of Earth's tectonic activity.

2) The world's tallest waterfall is Angel Falls in Venezuela, with a height of about 3,212 feet (979 meters).

3) The ancient city of Rome was founded in 753 BC and went on to become one of the most powerful and influential civilizations in history.

4) The European Union (EU) is a supranational organization comprising 27 member states that cooperate on various issues, including trade, economic integration, and common policies, while preserving individual national sovereignty.