Metatron's library

Metatron's library is an abandoned library in Blaine, Missouri used by Metatron to store Castiel's grace and the demon tablet.

Appearances

 * Season 10
 * Book of the Damned
 * Season 11
 * The Bad Seed (referenced)

Trivia

 * The location wasn't given until The Bad Seed when the Winchesters and Castiel discussed Metatron's escape from Castiel.