Pi Day (March 14) is a day of global mathematical celebration, but it’s not the only numerically significant calendar date.
Pi Day (3/14) often comes with sweet treats; Square Root Day (4/4/16 or 5/5/25, for example) has a certain numerical rhyme.
The ksar, a group of earthen buildings surrounded by high walls, is a traditional pre-Saharan habitat. The houses crowd together within the defensive walls, which are reinforced by corner towers.