DARIEN — Two men were arrested after police said they were found Saturday on an iconic, fenced-in property on Long Island Sound.

The Great Island property — listed for $120 million — is a 63-acre compound with a mile of coastline. A private driveway leads to a nine-bedroom manor house, an original 19th-century farmhouse, guest and caretaker houses and a “quaint” seaside cottage.

According to 6sqft.com, Great Island in Darien, is the largest private island to be offered for sale on the East Coast.

Because of its high value, the property is completely fenced in, with clearly posted “Private Property, Trespassers Prosecuted According to Law” signs throughout the property.

The property includes an equestrian center with an 18-stall granite stable with indoor and outdoor Grand Prix and Dressage arenas.

According to 6sqft.com, the property was first listed in 2016 for $175 million. The iconic property hadn’t been offered for sale or changed hands for more than a century. Purchased in the early 1900s by baking powder tycoon William Ziegler, the estate has remained in the family ever since.

The island is also closely watched by police.

At 4:30 p.m. Saturday, a police officer was on patrol after recent complaints of trespassing and vandalism on the property.

The officer found two men in their 20s walking on the property.

When the officer asked them what they were doing on the island, the men said they needed to use the property’s private dock so they could be picked up on a friend’s boat.

According to the property listing, the deep water dock can accommodate a 100-foot yacht.

The two identified themselves as Nick and Christopher Allam, of Fairfield, and New York City.

The officer became suspicious when he observed Nick Allam, 23, continuously put his hand in and out of his pocket in a nervous fashion, police said.

The officer then saw what he believed to be narcotics in a plastic bag sticking out of Nick Allam’s pocket, police said.

The officer removed the bag and observed the contents as psychedelic (aka magic) mushrooms, police said.

Nick Allam, of Old Dam Road in Fairfield, was charged with third-degree criminal trespass and possession of a hallucinogen.

While handcuffing him, the officer also saw that Christopher Allam become nervous, continually putting his hand in and out of his pocket, police said.

When the officer ordered him to take his hands out of his pockets and place them on the vehicle, Christopher Allam began running toward the boat dock, police said.

The officer was unable to chase him since he already had Nick Allam in custody.

When backup officers arrived, Christopher Allam returned to the area. Christopher Allam, 26, who lives in New York City, was charged with third-degree criminal trespass and interfering with an officer.

The two are due in court on Sept. 10.