1) The word "yesterday" contains three vowels: E, A, and A.

2) The human brain has a storage capacity equivalent to around 2.5 petabytes, which is roughly equivalent to three million hours of TV shows.

3) The Rocky Mountains, also known as the Rockies, extend from Canada through the United States, offering stunning landscapes and outdoor recreational opportunities.

4) 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.