Rodley Nature Reserve has been struck by arsonists twice in the space of just two days.
* Click here to sign up to free news and sport email alerts from Calverley Today.Volunteers have been left reeling following the damage that has gutted two birdwatching hides.
* Click here to become a fan of Calverley Today on Facebook.The first attack was on September 7 when a wooden bird hide on the willow path was completely burnt down.
The following night the vandals struck again and gutted a metal bird hide close by.
* Click here for latest Calverley news.They also made a bonfire out of kindling but that was found unlit.
Rodley Nature Reserve attracts around 20,000 visitors each year and is run entirely by volunteers who will be left to pick up the £2,000 bill for the damage.
Secretary Peter Murphy said that the police were informed straightaway after fearing that those responsible may strike again.
He said: "One of the bird hides has been completely destroyed but the other one can be repaired.
"It will take a lot of time and effort because the metal work is badly charred and the paint is flaking off. The wooden benches, floors and shutters have all been destroyed and will need replacing.
"We are very, very upset about this. It is a great shame that the actions of a mindless few should spoil the enjoyment of so many people."
A recent summer fair raised around £1,600 towards the work of the reserve but now more fundraising will take place to pay for the damage.
Volunteer Mandy Parker said: "The last thing that the reserve needs is unwanted damage and these people have destroyed something for the whole community.
"One of the hides was the best area for local schoolchildren to view the water area and losing this will have a big impact on their visit."
Insp Richard Cawkwell from Pudsey NPT said: "The Neighbourhood Policing Team (NPT) are currently investigating the arson where two bird hides were deliberately set ablaze.
"Patrols in the area have been stepped up and if any members of the public have any information they can report it to the NPT on 0113 241 4999 or contact Crimestoppers on 0800 555 111."
