The UK's intelligence, security and cyber agency creates a Christmas Challenge puzzle every year and this year marks a decade of challenges.

Riddles‍‌‍‍‌‍‌‍‍‌ are one of the best ways to make learning interesting. They develop kids' curiosity, require creative thinking, and make for a great, fun activity to spend time with your kids.

Every Sunday, NPR host Will Shortz, The New York Times’ crossword puzzle guru, gets to quiz thousands of listeners in a long-running segment called the Sunday Puzzle. While written to be solvable ...