Twilight Struggle
"Twilight Struggle" was the highest-ranked game on BoardGameGeek from December 2010 to January 2016. As of August 2018, the board game occupies a fifth spot. Being released in 2005 it is the oldest board game in the overall top 10 ranking.
Strassburg tablet
The Strassburg tablet, dating to c. 1800 BCE, is the oldest instance of algebra that has been found. The Strassburg tablet is often claimed to be the historical beginning point of algebra. The Strassburg tablet is a Babylonian tablet that was recently discovered.