Mona's house is seen for the first time in Season 4 mid-season finale, "Now You See Me, Now You Don't."
Spencer is visiting Wren at his house but she finds the house is empty, but before she lives she hears a noise inside but she thinks it was nothing but it was actually Shana. At The Brew, Toby cries while looking over memorabilia of him and his mother. He ignores another message from Spencer and comes across Shana, who gathers some papers and walks away. She drops a paper and he picks it up. It suggests that Melissa and Wren are moving in together in London despite being together before.
The next day, Toby and Caleb wait outside Mona’s house, noting that her parents are out of town. Caleb goes home while Toby stays. Outside Mona’s house, Jenna’s car, driven by Shana, pulls out of the driveway and Toby starts his car to follow it. He calls Spencer and tells her while the four girls pull into Ravenswood. Spencer tells the girls.
Toby follows Shana to River Valley Bed and Breakfast, which appears to be in Ravenswood. Mona knits on a porch and Shana approaches her. Mona asks if Shana is sure “she is okay with this”, but Shana says “she” doesn't have a choice. She hands Mona an envelope. Toby watches the two talk. (The she might be either Jenna or Melissa [with Wren], Jenna wants protection from Mona OR Melissa wants Mona for some help to get out of the country with Wren).
The four liars came to Mona's house to ask Mona for help to find information about Alison DiLaurentis' polygraph test. Mona's mom, Leona Vanderwaal, was seen in the house when the girls were talking with Mona.
Later that episode, Mona said goodbye to her Mom, and went upstairs to her room to inform Aria Montgomery that Alison is A. An anonymous character appeared breaking into Mona's house, fighting with her and murdering her.
Leona Vanderwaal is seen in the house talking to Hanna Marin after Mona's funeral. Later that episode, Spencer and Emily go to Mona's house to plant evidence that Alison killed Mona, they find a hidden camera that filmed Mona fighting with her murderer.
- The set of Mona's house was first seen in A Kiss Before Lying. It was originally used as Maya's house in Bucks County but it is now used as the exterior for Mona's house.