Originally Posted by FleetSnarl

Memento mori is also a big thing with Orthodox Christians and Catholics. It has been since the very earliest days of the Church. There's a several-hundred year old chapel in Poland whose walls are covered with 3,000 skulls called "Skull Chapel." The crypt below the chapel contains 21,000 skeletons. The idea is to remind people of their mortality. Today, there's a nun who's trying to raise awareness around the idea of memento mori, keeps a ceramic skull on her desk, and tweets something every day regarding our impending deaths.