1) The croissant, a flaky and buttery pastry, is an iconic French delicacy. It is made by layering dough with butter, rolling and folding it multiple times to create a laminated structure. The croissant can be enjoyed plain or filled with various ingredients, such as chocolate, almond paste, or ham and cheese. It has become popular worldwide and is a staple in breakfast menus and bakeries, symbolizing French culinary expertise and savoir-faire.

2) The Grand Canyon, located in Arizona, United States, is a massive and awe-inspiring natural formation carved by the Colorado River. It is approximately 446 kilometers (277 miles) long, up to 29 kilometers (18 miles) wide, and reaches a depth of over 1.8 kilometers (1.1 miles).

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 world's first stock exchange was established in Amsterdam in 1602.