STRICTLY speaking, Rhydymwyn Nature Reserve isn’t a park in the classic sense.
It is not always open to the public and you can’t kick a football around or have a picnic here.
But it offers much more than a square of grass and the odd clump of bushes.
I went along to visit Nigel Douglas, site manager, and Karl Martin, reserve officer, both of whom work for North East Wales Wildlife (NEWW).
NEWW is a charity which gains its funding from members of the public, as well as through Department for Environment, Food and Rural Affairs (DEFRA) and government support which helps them preserve sites of special scientific interest (SSRIs).
The NEWW team oversees several sites from St Asaph to Buckley to Johnstown in Wrexham, but Rhydymwyn was where it all started.
Mr Douglas said: “It’s not really like anywhere else. One of the things here is the mix of history and wildlife.”
The site is roughly a quarter-of-a-mile wide and a mile-and-a-half long. Wildlife surveyors have found that about 1,600 different species of mammals, birds, amphibians and invertebrates, as well as plants and fungi can be found in this small space.
There is an abundance of life here, which is made specially fascinating because the site was once a player in chemical warfare.
Mr Martin said: “There is a history of lead mining around here, but the site really started off as a Ministry of Supplies chemical manufacturing base set up during the Second World War.
“It was used to make and store chemical weapons, particularly mustard gas, and people in the area weren’t even given a clue what was going on. It really was one of Britain’s top secret sites.”
In the 60s, the area, and the buildings on it, were given over to industrial storage, what Mr Martin called a “very quiet existence”.
In the late 90s, things changed.
Mr Martin said: “That was when the information about the site was released to the public. There was an investigation and talks about what could be done with the place.
“In 2004, the majority of the buildings were demolished and it became a nature reserve, and we’ve been here ever since.”
It’s touching that an area once given over to the creation of weaponry should become a haven for all kinds of life.
We took a stroll through the reserve, moving away from the small cabin where the staff members are based, past a military building converted into a school room and along a concrete path.
It might seem odd that a nature reserve is served by asphalt – it's a remnant of the site’s earlier use. It is not natural, but on the plus side, it makes it easy for staff to get around when they are copicing, planting, putting up bird boxes, experimenting with animal shelters or conducting studies.
One of the most recent studies was performed by members of the Butterfly Conservation Group, whose numbers show that this has been a bumper year for the insects.
Mr Martin said: “They’ve had a difficult few years, but according to the survey, the numbers have gone up by several hundred per cent, which is great.
“It’s good to see how nature can bounce back.”
It is a pleasant walk. Gatekeeper, cabbage white, peacock and common blue butterflies fluttered about. Overhead, a buzzard menaced a brace of smaller birds.
One of the reasons parks are loved is because they give us the opportunity to enjoy green spaces.
Mr Douglas said: “Why have a park? We think it’s particularly important to connect people with nature. Often you find at schools that youngsters are taught about ecology in quite an abstract way.
“They’ll study the Brazilian rainforest, which is quite distant from their own lives. When they come here, they can witness local nature at work.
“We have volunteer days where people can come and get their hands dirty, we hold events and we offer school visits.
“Individuals can book a visit with us as well.”
Mr Martin added: “Even though we live in quite a rural part of the world, you’d be amazed how often this is a first-time experience for a child. Many of them have only encountered green through the football field at school.”
Rhydymwyn Nature Reserve is an example of the effects intervention can have on an ecosystem, both negative and very positive.
Workers at the reserve have to keep an eye out for invasives like Himalayan Balsam, which is brought into the park by the River Alyn, and rhodedendrons, fast-growing plants that crowd out native species if given a foothold.
In contrast, the abandoned ex-military buildings have been colonised in a good way.
The buildings where workers used to put mustard gas into shells still stand – graffiti dating back to the Second World War is still visible on the walls.
Mr Martin said: “The operation was so secret they couldn’t use notebooks, so they wrote a lot of their workings-out on the walls. You can see the names of chemicals and notes about the weights of ingredients on there.”
Thankfully, the weapons were never actually used and some of the buildings now provide homes for different species of bat, including the vulnerable Lesser Horseshoe.
Towers that once held what Mr Martin joked was “extra concentrated orange juice” are now set up for sand martins to nest in.
There is an expansive wetland area which plays host to coots and moorhens, a grassland beloved of the butterflies and wooded areas which shelter foxes and badgers.
Damselflies and other hovering insects frequent a small pond, the damselflies zipping around like busy blue twigs.
Sharp eyed staff even noticed a growth of yellow bird’s nest (Monotropa hypopitys) near their cabin.The rare plant is not green because it has no chlorophyll. Unlike most plants, it finds its food as a parasite, gaining nutrients from fungi, which in turn have a symbiotic relationship with trees.
Mr Martin, who knows the park well, was able to reveal a toad in hiding, and a young newt sheltering from the morning sun beneath a log.
If anyone needs convincing of the value of green spaces, Rhydymwyn Nature Reserve is the place to go.