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 Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

3) The word "music" contains two vowels: U and I.

4) The first graphical web browser, Mosaic, was released in 1993 and played a key role in popularizing the World Wide Web.