That... looks... awesome.
Before doing this the store had the common painted concrete floor. But after fifty hours of work by twelve volunteers to place and coat 6,882 unique cards, they ended up with this awesome-looking floor.
Among the cards on their floor, one player donated an Old Man of the Sea. But lest you fear countless rares died so that they could have this floor, fear not, there are also 250 Lava Axes as well as cards from other games entombed here forever.
Thanks to Kyle for sharing this with us!