On the passion facade of La Sagrada Familia, the magnificent cathedral in Barcelona, Spain, you’ll spot this odd grid of numbers. Designed and placed here by the cathedral’s architect, Antoni Gaudi, this is known as a “magic square.”

Why is this so special? Try adding the numbers in any direction and discover the sum (the bottom number on the right is 15 – apologies for my photography). Then, think about what significance that sum has in a cathedral dedicated to the glory of God.

Gaudi used a variety of imagery, light and shapes to draw the visitor’s attention and devotion to God when they walked through his cathedral. In my mind, this square represents a clever way to catch your attention and entice you to give thought to the image of the invisible God.

Still stumped? Shoot me a note and I’ll fill you in on the secret.