The Chestnut Hill-based Sisters of St. Joseph said Monday they have agreed to sell their sprawling, historic 138-bedroom retreat house overlooking the ocean in Cape May Point to a newly formed environmental nonprofit.

The Cape May Science Center intends to create an environmental center at Saint Mary-by-the-Sea devoted to conservation in concert with the nuns’ “commitment to the ocean, climate and marine life,” according to an announcement of the deal.

The nonprofit has agreed to preserve the three-story, 38,000-square-foot structure. It also agreed that the land would never be built on if the building is ever “destroyed by nature,” according to a news release by the sisters.

A deed restriction bans any new development. Closing is expected early next year.

The Sisters of St. Joseph, a Roman Catholic order of nuns, have owned and operated the retreat house since 1909, hosting both nuns and laity.

In 2016, the sisters announced plans to close the house, with its commanding view of the Atlantic Ocean and its confluence with the Delaware Bay, after the 2022 retreat season. However, the pandemic hastened the process.

» READ MORE: Sisters of St. Joseph close iconic Cape May retreat: ‘It’s beyond sad’

The property is assessed at $4.1 million. The price of the deal was not disclosed.

The retreat house is tax exempt and located in a low-density residential zone.

Saint Mary by-the-Sea has a storied history, that begins with what was originally the Shoreham Hotel built in 1889, according to stmarybythesea.org, a website devoted to the house’s history.

The prior to the hotel’s construction, was once a stop on the Underground Railroad, where enslaved people escaping Maryland landed to proceed north. site was once a stop on the Underground Railroad, where enslaved people escaping Maryland landed to proceed north.

The U-shaped Saint Mary by-the-Sea — considerably modified since it was first constructed in 1889 — has 1,200 linear feet of porches and a 200-foot lawn that spills onto the beach.

The religious order had been looking for a way to sell the property, one block from the historic Cape May Lighthouse, while preventing it from being developed. It hired an attorney who specialized in conservation deals.

The sisters originally thought they might raze the old building, with the goal of returning the land to its natural state. But they found out the structure was in no immediate danger from the ocean, so they modified their plans to preserve the iconic red-roofed building.

The Cape May Point Science Center Inc. was awarded nonprofit status by the IRS this year. It was established by Robert Mullock, a former Cape May Point borough commissioner.

Mullock, who owns Cape May National Golf Club and the Chalfonte Hotel in Cape May, also helped establish the Harriet Tubman Museum of Cape May.

“I’ve just got to say what heroes the sisters have been with this,” Mullock said. “They could have taken this building and sold it off to some big hotel group and brought in a lot of money. But they didn’t.”

Mullock’s nonprofit plans to turn the retreat house into The Cape May Point Science Center, and offer educational and scientific programming in line with its mission statement “to inspire conservation, protection and environmental restoration in an ecological and scientific approach to the ornithology, marine and botany of the regional east coast environment through research, education and advocacy.”

He said the nuns have taken care of the building. The exterior is in good condition, he said, but the interior will need to be modernized, though Mullock did not specify a scope of work.

The nonprofit will begin raising money soon and Mullock said it already has a lot of interest.

Mullock said he was inspired by a Pope Francis encyclical that called for religions to join together over climate change. He said Cape May Point, at the very tip of New Jersey, is in a prime position for people to learn about climate change and so many other important topics, such as the Underground Railroad, bird and monarch butterfly migrations, as well as habitat for wales and dolphins.

He noted that the timing is fortuitous: Pope Francis named 2021 the Year of St. Joseph to recall the 150th anniversary of the declaration of St. Joseph as Patron of the Church.

The Sisters of St. Joseph Chestnut Hill has about 600 members from 12 states in its congregation. It traces its roots to 1650 in LePuy, France, and was established in Philadelphia in 1847.