Arkham’s inept security was a recurrent theme from early on, though. Somehow, the guards failed to notice the fact that the Joker turned his padded cell into an elevator and built an entire criminal hideout under the asylum, which he called the “Ha-Hacienda.”
At first, Arkham’s backstory was “eh, it’s a building, who cares.” But everyone and everything in comics must have an elaborate secret origin, and in 1985 Arkham got a pretty dark one: turns out it was founded by Amadeus Arkham, whose wife and daughter were killed by one of the asylum’s first inmates, and it’s implied that Amadeus fried the guy’s brains in retaliation. Amadeus ended up becoming an inmate himself, and he didn’t just go crazy — he went “carving indecipherable inscriptions on the floor of his cell with his fingernails” crazy.
In 1989, the acclaimed Arkham Asylum: A Serious House on Serious Earth graphic novel expanded on this sad tale and established that the “inscriptions” were part of a spell created by Arkham to bind some sort of bat demon that haunted the place. It was also around this time that artists started drawing Arkham like everyone in it is constantly having the worst acid trip of their life, which might explain why so many asylum employees end up going nuts.
DC Comics