MONTAUK - With a radar dish rising above the dunes in Montauk and signs once warning visitors to keep out, Camp Hero actually played an important part in America’s military history.

Now overgrown and abandoned, the once top-secret military base kept invaders out of the country during World War II, says Montauk historian Henry Osmers.

“It was actually part of what they call the East Coast defense shield,” Osmers says. “Strategic locations up and down the East Coast of the United States, basically keeping an eye on things and making sure that there were no surprises.”

Also a secret at Camp Hero, the underground tunnels that used to help connect batteries containing cannons. And in ‘downtown Camp Hero,’ Osmers says a cluster of buildings were disguised to look like a New England fishing village from the air.

After World War II ended, Camp Hero continued to be a strategic military location. The radar dish was built by the Air Force in 1960. It had the ability to detect aircraft up to 280 miles away, according to Osmers. In 1981, Camp Hero was decommissioned and is now a New York State Park.

Osmers, who wrote a book on the site’s history, hopes it will be remembered for the role it played in protecting the country.