1) Banks play a vital role in the economy by facilitating the flow of funds between savers and borrowers, providing loans, and offering various financial services.

2) The highest-grossing concert tour of all time is U2's "360° Tour," which earned over $735 million in ticket sales.

3) In Norse mythology, the Valkyries are divine maidens who serve Odin, the chief god. They are responsible for selecting warriors worthy of entering Valhalla and escorting them to the afterlife. They are often depicted as powerful and beautiful figures, riding winged horses and wielding spears.

4) 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.