|“||This is "A's" lair.||„|
|~ Spencer in UnmAsked|
In UnmAsked it is revealed that Mona's lair is located in Room 2 at the Lost Woods resort. After Mona is revealed the next day the liars go to empty it out, but everything is gone. Presumably Toby took it all to their new lair.
In The Lady Killer it is revealed that Toby and Mona's new lair is located in an apartment building in Room A. When Hanna and Spencer have the key for the lair Spencer goes to it after Toby is revealed as A and opens it up to finds it empty.
In Season 3B it is revealed that Toby has moved everything to a mobile RV which he and Mona can drive wherever they need. It has all their electronics and pictures and everything stored in their and is usually parked in a trailer park unless Mona or Toby are driving it. In A DAngerous Game, Spencer is in the lair on the computer getting Toby's "A" number.
After Toby gives the RV to the Black Widow she has moved everything into her apartment and this apartment is seen in Miss Me x100 and She is moving in and her Black Widow costume is hung up on the wall. It is also seen when she is playing with her dollhouse playing out how Alison goes to jail and the liars to the dollhouse.
In Welcome to the Dollhouse it is revealed to the police that A's lair is located in a secret underground area in the campbell farm. This is not A's main lair but mostly a viewing room for the dollhouse camera system. A watches the liars when they are inside the dollhouse 24/7. In Game On, Charles after the liars light up Charles's vault in the dollhouse they pull down a curtain to find Charles watching them from his lair. It is possible that Tyler State Elementary Park and The Campbell Farm are connected if his lair is viewable from the dollhouse. It is possible that Charles/The Black Widow have moved the lair if the dollhouse was on fire.
After the dollhouse went up in flames Charlotte moved her stuff to the Charissimi Group her business and had it inside a secret room which had a panel that opened into a room with a transparent screen and large computer.
A's lair is the lair for "A" and the A-Team to use for their mission planning. The lair was originated in 2008 by Mona Vanderwaal, who was the first "A". The idea was later taken over by Big A and The Black Widow who have had various lairs.
The Liars (sans Emily) return to the lair to empty it out but find it completely empty. Spencer continues to visit the lair to figure out where everything was and put the pieces together. Later, all four Liars return to the lair, where they break the news to a clueless Emily. Here, "A" litters their car with photos and sends them a text.
The A-Team settles into their new lair, which is very similar to the last one.