When grandad John Bostock was tidying an overgrown part of his garden he could hardly believe what he uncovered.
He was stunned to find an 18th century Gothic folly still intact – and decorated with oyster shells, and bones and teeth from cows and sheep.
The homeowner was stunned to uncover the beautiful structure hidden at the end of his suburban back garden at the house where he has lived for 25 years.
The 62-year-old had been pruning ivy and tidying up his garden ahead of moving house when he made the incredible discovery on Saturday, July 3.
The striking 12ft (3.5m) ornate brick structure is decorated with oyster shells, bones and teeth from cows and sheep and includes windows and an archway at the front.
It is believed to date back to the mid-1700s when aristocrats built decorative follies as garden features to admire from the main house.
Experts told John a woman of the house may have used the grotto to relax to get away from the hustle and bustle of a manor house which once stood on the site.
The perfectly-intact back yard folly in leafy Edgbaston, Birmingham, is just half a mile away from one of the city’s most famous landmarks Perrott’s Folly.
It was said to be the inspiration for J.R.R. Tolkien in his writing of the Lord of the Rings trilogy.
Dad-of-five John, who lives with his wife Deb, 57, said: “We knew something was down there but not on this scale. I couldn’t believe the condition it was in.
“We have been in the property for 25 years, but the garden had become a bit overgrown and it was covered in ivy.
“I started to do some clearing and removed the ivy from it to uncover it then one thing led to another.
“I realised it was something I had to showcase.
“It was a bit of the garden we left to run wild and there is wildlife like badgers down there, it was left to nature until now.
“I didn’t really know what it was so I got my daughter-in-law to take some photos which we put on social media.
“All of sudden we could see the numbers going up and they were generating a lot of interest.
“Then we had a couple of people come up to the house, one from the National Trust and a local historian.
“As soon as they looked at it I knew it was something special because they were gobsmacked.
“They said in all their years visiting historic gardens in Birmingham they had never seen anything like it.
“They were amazed how well preserved it was on the outside and that some of the bricks look Georgian although the wood bits inside have been lost to time.
“They estimate it is from the mid 1700s but they need to do more research because there is still a lot of stuff to uncover.
“I had no clue how old it was, I’d always thought it was something imitated from history and had no clue how much actual history is there.
“It was amazing to find on our doorstep and just a mile away from Birmingham city centre.
“We think it is something that other people need to see and that it needs to be protected.”
John, who works in digital engagement, is selling the six bedroomed house and had already accepted an offer before realising the folly was on his half acre plot.
The grandfather-of-one added: “The house is up for sale and an offer is in, but I’m a man of my word.
“I must admit it’s hard to leave it because we are attached to the property but the folly is going to a good home and the new owners will look after it I’m sure.
“The experts are still researching to try to find out what it was for.
“They’re saying like other follies it is quite likely it was a secluded area to go down to relax and maybe the lady of the manor would go down there for a bit of peace and quiet.
“So there is a health and wellbeing element to it which is very timely in these days and people do seem relaxed in this sort of space.”
National Trust senior gardens adviser Pam Smith, who visited the building, said: “I’ve been in Birmingham 24 years and I think this is one of my best days.
“It certainly was a highlight in my career and I’m pleased it has prompted such interest.
“It’s beautiful. Everyone loves discovering something that has been lost and this has been lost for quite a while.
“It just a privilege to be some of the early people to see it in this state, because sometimes when things get restored, they lost a bit of romanticism.
“It is an opportunity to remind people that gardens are about pleasure and quirky tastes as much about the ‘10 minute jobs in your garden’ – that always sound to me like a chore rather than a creative and satisfying hobby.
“Follies such as this are a great place to sit and also show the playfulness of garden creators of the past.
“In terms of what we know – it isn’t much but I am keen to help them find out more.
“It seems to be constructed from oyster shells and bones and teeth from cows and sheep.
“They used whatever was to hand from local slaughter houses and butchers, quite often it was sheep bones and sometime cows.
“The teeth could be from cows but the bigger ones are probably sheep.
“Our next steps will be to look at old maps, the house that was on the site before the current owner and find out about the family.
“Such shell work could have been done as a hobby project for the ladies of the house.”
Garden historian Advolly Richmond added: “It’s obviously a shell house as opposed to a grotto, because grottos tend to be more subterranean.
“It’s absolutely gorgeous inside. A lot of the teeth are still intact, and the bones are just pristine.”
A National Trust spokesperson said: “Even in the gardens of the National Trust we have many unanswered questions, many garden features, including follies, that are long lost and known about only in letters and sketches.
“Follies and grottoes capture the imagination of all our gardeners and visitors, they were about pleasure, fun, secrecy and surprise.
“We all long for that hideaway at the bottom of the garden and this discovery in an Edgbaston garden is a little less hidden than a week ago and has yet to reveal its secrets.
“We look forward to helping to find out more and hope to help to ensure its survival for the future.”