Private island, 6.5 acres of complete solitude in the middle of the Hudson River — majestic water and mountain views from your own historic castle, convenient to Midtown via Metro-North, bring your contractor!

Right, so maybe one of the most dramatically situated pieces of real estate within commuting distance of NYC isn’t for sale, and definitely don’t upset any development-averse locals by bringing your contractor, but don’t let that stop you from from visiting and appreciating Bannerman Castle — jewel-in-the-rough of New York’s Hudson Highlands region — anytime you like.

Best of all, you don’t even have to get in a car.

Linked to the heart of the Big Apple via Metro-North’s Hudson Line, all year long — that and a boat shuttle departing the docks near the Beacon train station — this architectural oddity, over a century old, remains the focal point of life on little Pollepel Island all these years later.

For such a small landmass, Pollepel has enjoyed a varied and colorful history, earning its stripes as a strategic site for holding the British back (at least for a time) during the Revolutionary War. In more modern times, it became a storehouse for a military surplus dealer based in Brooklyn, an immigrant from the British Isles named Francis Bannerman.

The remnants of that structure are what Hudson Valley residents now refer to as “the castle.”

And while those riding the train — passing just a stone’s throw away on the eastern bank of the Hudson — might not know to look at it, the Island is much more than its crumbling ruins.

In this diminutive paradise, there are gardens, appealing nature trails and picturesque viewpoints for all the photo and video you can take. The island hosts a full series of cultural events, along with year-round tours, conducted on foot, by boat and even kayak.

Essentially left to rot for the latter part of the 20th century, the island is now managed by the Bannerman Castle Trust, which, in partnership with New York State, has made continued investments in the site — new funds were just announced for additional improvements, prior to the summer season.

Getting there is easy — hop the Hudson Line train from Grand Central Terminal to Beacon, which can take anywhere from a bit over an hour to about 90 minutes, depending on the time of day.

Once in Beacon, the island’s trusty Estuary Steward boat will take you the rest of the way — a scenic, 30-minute ride toward Storm King Mountain, where the river shrinks down to truly earn its title as the only recognized fjord in the Eastern United States.

What to do once you’re there? Read on:

For more information, visit bannermancastle.org.