More than 100 academics have signed a letter to The Times saying the code-cracking centre and crucible of the UK computer industry deserves better.
They say Bletchley, Buckinghamshire, should be put on a secure financial basis like other "great museums".
"We cannot allow this crucial and unique piece of both British and World heritage to be neglected in this way," the letter to The Times said.
Inside Bletchley Park
The academics were brought together by Dr Sue Black, head of the computer science department at the University of Westminster, who was moved to act after visiting Bletchley Park in early July.
"I went up there and felt quite upset by what I saw," she said.
Many of the buildings on the Bletchley estate were in a state of serious disrepair, she said. One building, where code-breakers worked during World War II, was falling apart, said Dr Black, and was protected by a blue tarpaulin that was nailed down over it.
Describing Bletchley as a "gem", Dr Black said it was a "national disgrace" that such a historic site was being allowed to fall into ruin.
Celebrating the UK's computer pioneers
"I do not know why they do not have funding as a national museum," she said.
The visit led her to contact other heads of computer science departments at universities up and down the country. Within hours, she had hundreds of responses - all of them backing her call.
Dr Black said she had been "overwhelmed" by the response which showed the depth of feeling about Bletchley and the position it occupies in the history of the computer age.
Bletchley Park is well known as the place where the Enigma codes were broken but it is also the place where Colossus was created - a machine that was the forerunner of many modern computers.
The engineers that worked on Colossus at Bletchley helped define and develop the UK computer industry after WWII ended, said Dr Black.
What was needed, she said, was for Bletchley Park to get secure funding from the government. Until recently the site was deemed ineligible for Lottery funding that would help preserve it.
A change to the rules on who can get funds has led to negotiations with the Lottery Fund. However, said Dr Black, it could still take up to a year for funds to materialise.
In the meantime, said Dr Black, the site was falling into an ever worse state of disrepair.