1) The Iguazu Falls, located on the border between Argentina and Brazil, is a majestic waterfall system consisting of numerous cascades and islets. It is a UNESCO World Heritage site and one of the most impressive natural wonders in the world, attracting millions of visitors each year.

2) The Beatles hold the record for the most number-one hits on the Billboard Hot 100 chart, with 20 songs reaching the top spot.

3) Cows have best friends and can become stressed if they are separated.

4) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.