LOTS of people have unusual hobbies but Angela Barnes takes it to another level.

The Brighton-born comic researches and visits Cold War nuclear bunkers, and such is her fascination with these now abandoned concrete structures that she spent her 40th birthday in one. Her boyfriend surprised her with the trip in November 2016.

“He whisked me away to this bunker in the middle of Monmouthshire, which has been converted into a little guesthouse,” she says. Their visit coincided with the election of Donald Trump. “When we woke up and learned he’d been elected we looked at each other and said, ‘We’ll stay here’.”

She recounts the tale in her new show, Fortitude. While bunkers feature in the routine, it is much more about the passing of time.

“I wanted to write something about turning 40 but I didn’t want it to be a show simply in which a middle-aged woman talks about middle-aged woman things,” says Barnes. “I wanted to talk about how people treat you when you are a childless woman, and more broadly about what it’s like to turn 40 in today’s society.”

Barnes is only one year into her 40s but is so far “loving it”. “I think the pressure’s off,” she adds. “People will eventually stop asking me about having children and I know I can do all sorts of things when I feel ready.”

The comedian describes herself as “part of the Peter Pan generation” that don’t feel as compelled to grow up or settle down as their parents might have done.

“Having said that, I wouldn’t want to be a millennial for anything,” she says, “what with the pressures of social media, not being able to afford a house or what will happen with Brexit.”

Barnes came to comedy relatively late. She was 33 when she started gigging in 2009 before winning the BBC New Comedy Award in 2011. She quickly established herself on the circuit and is now a regular guest on topical panel shows such as BBC’s Mock the Week and The News Quiz.

The Londoner, who recently moved to Brighton, trained as a nurse and later worked in mental health and social care with people in hostels and those suffering with substance abuse. Barnes’s family, meanwhile, has provided some rich material – her father ran a sex shop and she knew he was a naturist, but it was only after his death that she discovered he was a swinger too.

His story formed the core of You Can’t Take It With You, her debut show at the Edinburgh Fringe in 2014. Barnes has also talked on stage about spending time in a psychiatric ward when she was a teenager. Does she worry that her comedy might be too revealing, or too personal?

“No,” she says, “because unless your show is surreal or character comedy, it needs to be relatable to people. They want to go away thinking they know you. Otherwise it’s just me talking at them – how arrogant is that?”

Barnes first performed Fortitude at the Edinburgh Fringe last August. The run gave her an excuse to hunt down another nuclear bunker, this time in nearby Fife, and do a gig there. “It had room for 15 people so three other comics and I hired a minibus and we took the punters there,” she says.

Barnes would love to own one of these structures, although her boyfriend is not so keen. “One came up for sale recently and I sent him the link. He ignored it.”

Angela Barnes: Fortitude Ropetackle Arts Centre, Shoreham, Thursday, 8pm. For tickets and more information visit ropetacklecentre.co.uk