Vines snake across the crumbling brickwork and it's no less foreboding inside - a chilly atmosphere pervades the entire structure. Rumour has it that the new 'Bedlam Heights' is haunted for real - throughout the two-and-a-half month shoot, crew members have reported spooky sightings and the mysterious sound of a unseen bell chiming...
"It's so scary!" admits new Bedlam lead Lacey Turner, who plays paramedic Ellie. "It's huge this place. Stunning, but seriously scary. We had a power cut three weeks ago and I ran around screaming, 'Oh my God!' - I was petrified.
"People have seen things here," she adds. "There has to be something!"
Thankfully, it's courageous Ellie and not Lacey herself who has to brave the paranormal in series two. "I'm scared of my own shadow," the actress confesses. "I'm scared of everything! But Ellie's not, which is nice, because I get to do things that I would never do myself. I would never walk down a corridor that is dark. Never!"
Jack Roth, star of Sky1's The Cafe and son of Hollywood star Tim Roth, agrees with his co-star's assessment of their spooky set. "The building's horrible," laughs Jack. "You walk around it and you kind of do get lost. It gets dark and cold, but it's so much easier to let yourself be scared!"
Of her role as Ellie, who has the special ability to see ghosts, Lacey says, "She's just a normal girl fighting for a normal life, but she has this supernatural side to her the whole time.
"She's quite a tough cookie. She has quite a lot of barriers that she puts up, but she develops quite a lovely relationship with Jack, who plays Max. I really enjoy that part of it, that you don't see with anyone else."
Jack himself adds that Max, a bartender with an avid interest in the supernatural, is "a really gentle character".
"He's probably one of the most honest characters I've ever played," Roth explains. "You know, I'm used to playing like very extreme characters and with him, it's really lovely to nestle into something different.
"I think it's great for Ellie to be able to share [her powers] with someone who totally believes it. It's a really nice thing, cos otherwise everyone just thinks she's mental!"
But will things go any further between pals Ellie and Max? "We just don't know," says Jack. "It's organic. I'd rather people hope we get together - that's far more interesting, I think."
A veteran of stage, screen and theatre, Jack told us that he was initially "the biggest critic" of former soap star Lacey, but was won over by her performance in series two of Bedlam. He says: "She looks you in the eye sometimes and you think, 'I really believe this'. It's great."
"I wasn't into Twilight or any of that," she reveals. "But then I got massively into [that genre] after Being Human. I tend to watch more supernatural stuff now. It's nice. It makes a change from your average series."
Of course, with a new cast on board - Nikesh Patel, Gemma Chan and series one veteran Hugo Speer join Lacey and Jack - fans of Bedlam's first incarnation may be wondering how the new episodes are related to the 2011 series.
"We've all kind of come in and it's almost like we get to lay our own names on it and really kind of do what we wanna do," suggests Jack.
"You know, the first series was brilliant and we hope the second will be good because it mixes it up a bit," Lacey explains."But hopefully it'll be darker and scarier. A continuation of the journey that you had glimpses of in the first series."
Bedlam returns to Sky Living on Wednesday (June 6) at 10pm and is available on the move with Sky Go.