Waterford — A group of developers, architects and engineers got a glimpse Monday inside the four buildings at the former Seaside Regional Center that the state hopes someone will want to turn into a hotel resort.

The tour, which the Department of Energy and Environmental Protection advertised as a tour for "prospective proposers" interested in bidding on a 50-year lease with the state to run Seaside as a hotel within a state park, brought about 16 people to the property Monday morning.

The group included at least three representatives of real estate development firms, including Londregan Commercial Real Estate Group, Madison-based Resort Realty and a third Connecticut development company whose president declined to identify it.

DEEP spokesman Chris Collibee said participating was not a requirement for developers seeking to submit a bid, and the participants in Monday's tour do not necessarily represent the bidders who will eventually submit proposals to the state by the July 27 deadline.

The group walked through all four historic buildings on the Seaside property, which were designed by the architect Cass Gilbert in the 1930s and were listed on the National Register of Historic Places in 1995.

All participants signed waivers acknowledging the risk of walking through the more than 80-year-old buildings, which are fenced off and closed to the public. The grounds around the buildings, including a sloping grass lawn, walking paths and a small beach, remain open to pedestrians; on Monday afternoon bird-watchers, anglers and dog-walkers strolled by during the tour.

The group touring the buildings Monday also included Anthony Morascini, who was one of three bidders to develop New London's Lighthouse Inn in 2016, along with employees of the Connecticut Trust For Historic Preservation, the State Historic Preservation Office and the president of a local photography club.

DEEP officials and contractors guided a Day reporter and photographer on a second walk through the main former hospital building after the tour for potential developers.

Chris Walker of Resort Realty said he came on the tour to learn more about the property.

"You have a great opportunity here with the waterfront," he said. But, he said, the buildings' age could be a deterrent.

The four Cass Gilbert buildings were built in 1934. While state-contracted architects have declared the buildings stable and salvageable, the original structures and their additions have been empty and left damaged by animals, human trespassers and the elements since 1996.

The state has hired contractors to remove asbestos-ridden walls and large quantities of garbage left over from the property's three decades as a residential center for people with developmental disabilities. But the asbestos abatement is only about two-thirds completed, and the experts who toured the buildings Monday said there's much more work to be done.

Graffiti covers the walls on all four stories of the main building where people have sneaked past "no trespassing" signs. Large holes riddle many of the floors and plywood covers the windows. Animals have taken up residence in the chimneys and cupola.

"It's a big challenge," Walker said. "I think there's going to be reluctance to take this on."

After Gov. Dannel P. Malloy announced Seaside would become a state park in 2014, state officials spent more than three years weighing options for the future of the property, originally a tuberculosis sanatorium.

In January they released an official decision that the the state would seek a partnership with a private developer who will renovate the historic Seaside buildings into a hotel with public access to the grounds.

Steven Iovanna, an architect with the architectural engineering firm Michael Baker International, said his company is in contact with several developers and looking for a partner with whom to submit a bid to the state.

"I think it's an amazing opportunity," he said. As an architect, he said, "you want to see these buildings up and thriving and renovated."

The president of the unidentified development company present Monday said he saw promise in the property but added that the state's latest study estimating that rehabilitiating buildings would cost up to $30 million was too low based on the condition of the buildings.

"That's very, very light," he said.

The state's request for proposals released in March requires at least a 50-year lease of the buildings for a hotel with up to 100 rooms, and leaves the rest of the park and beach open to the public.

The ideal proposal would "offer amenities such as dining, meeting space, and a spa, and make the site an attractive destination that works in harmony with adjacent neighbors, the community, and nearby park properties," according to the request.

m.shanahan@theday.com