The Hillandale Estate/Sisters of St. John Orphanage & School

Somerset County is home to some of the most attractive and expensive residential homes in the state of New Jersey. Some of these estates are relatively new, while others were built centuries ago. The subject of this article, the Hillandale Estate, falls into the second category. 

Source: TFPNJ Postcard Archive

The foundation was laid for the beautiful mansion in 1906. Once completed, the structure would be home to George Mosle and his wife Katherine. Mostle was a wealthy sugar importer who made his fortune brokering sales with Cuban sugar plantations. Architect Grosvenor Atterbury designed the home in a handsome Craftsman style.

Like many other industrialists of the time, Mosle's business relied heavily on imports. This became a real problem for him when the first World War broke out. The company lost so many ships during the turmoil that by 1926 Goerge Mosle had to declare bankrupcy and leave Hillandale. 

The mansion and grounds were purchased by the Sisters of St. John the Baptist, a Roman Catholic organization. They quickly got to work transforming the property to better suit their needs. They cleared land for farming and added two new wings to either side of the home. The most impressive new feature was the large, well decorated chapel on the south wing. By the time construction was complete, the building was an intimidating 66,000 square feet.

The sisters operated an orphange at the convent for nearly a decade. After ending the program in 1937 they began to focus mainly on education. Private schools were relatively common in the Somerset Hills at the time. The St. John campus was not far from the well established St. Bernard School for boys, and the newly established Wychwood School for Girls as well The new St. John Academy boarding school became home to many catholic children from the area. 

Thirty sisters called St. John's home at its peak. By the 1950s an entire new school building was built along the driveway leading to the main building. The greatest feature of the structure was definitely the full sized gymnasium. Unfortunately the success of the educational instition began to wane over the decades. By 1992 the academy had closed, and the space was being rented to a different private school named the Montgomery Academy. 

In an attempt to raise funds the sisters sold a portion of the estate for $15 million to Morris County. They built a new sports field which they dubbed Mosle field in honor of George Mosle. There were only seven sisters still living at the facility by this time. Montgomery Academy found a new home in Basking Ridge three years later, leaving the large main St John's building mostly empty. More land was sold to the county, which became the Mosle preserve. The last few sisters moved out in 2013, and the property was put up for sale for nearly five million dollars. 

It wasn't until the following year that I first saw a photo of the outside of the main building. I had just created an account on Reddit and was busy skimming through all of the posts on the exploring boards that referenced New Jersey. Someone had posted the outside and labeled it "abandoned boarding school New Jersey". Inside the comments the user had mentioned that the local kids would go up to the school and dare each other to sneak inside the empty buildings. They also mentioned it was somewhere near Peapack-Gladstone. It was definitely the thing that stood out the most to me from this bout of research. I spent hours looking for the building, to no avail. I didn't end up tracking it down until 2015.

I was so happy to finally have found the place. I took the first opportunity I had to drive over to the place. I parked at the sports field and began to walk over. The property was quiet as I approached the structure. The first door I passed was just sitting ajar. I couldn't believe my luck! I popped inside, and was quickly met with the smell of Pine Sol and the sound of running fans. Lights were on in the basement, and I could hear the old steam system creaking and groaning. This building was absolutely not abandoned, but vacant. I wasn't very accustomed to being inside buildings like that before so I was quite nervous. I took my chances and bee lined it for the large, beautiful chapel I saw on the aerial view.  I got a few photos quickly and left before anyone figured out I was there. I came back with some friends shortly afterwards take some time to see more of the place.

The door I had left unlocked was shut again, but I was able to find another way in swiftly. We wandered around for a while, starting in the school and working our way through the mansion to the chapel.  At one point we ended up in an office in the front of the building. I looked at the calendar and was shocked to see it was marked for the exact day we were there. We quickly realized this was the caretakers active office and we needed to leave immediately. Around this time a developer named Jeffery Toia came forward with a solid plan to reuse the building. As reported in the Observer - Tribune, "The master plan creates a sense of estate, Toia said. “The mansion and school buildings being the castle so to speak and the townhouses being the village framing the castle. The existing rock walls and open spaces can then capture a whole host of activities that make up daily life. Architecturally, the materials for the townhouses mimic the original mansion with stone, brick and batten board.” Unfortunately his plan was shot down by the township. I don't think they had any idea what a mistake that was going to end up being.

A few years later the place regrettably turned up on Instagram. After seeing several of the usual "urban tourists" going we decided to revisit again before it started to get ruined. I was pleasantly surprised to see everything more or less in place, with the exception of some antique hardware going missing. We took our photos and headed out, assuming we would be able to come back at some point. Unfortunately that wasn't the case. I had missed an article that had come out in 2021 acknowledging that the entire campus, including the mansion, was to be demolished. In September 2022 I saw it posted on Instagram by @lockjaw.ny with the caption "RIP" and bugged out. Before long I was back at the property to see for myself. I drove right up the driveway and parked amongst the workers on the land where the mansion once stood. I was extremely distressed. There was absolutely no reason the mansion had to be demolished. This is yet another example of developer K Hovnanian Homes destroying an irreplaceable part of New Jersey's history to serve their own greed. The new development, disgustingly called "the Enclave at Hillandale", is a cluster of tacky, soulless buildings constructed quick and cheap. Surely they won't last as long as the incredible mansion that once graced the same land.