You can call this “castle” your home — and for a bargain, to boot.

Perched above the river that divides Virginia and Maryland, a 16,800-square-foot mansion dubbed the Castle on the Potomac boasts eight bedrooms, 12 bathrooms — even a concrete-encased safe room underneath the indoor swimming pool. Located in affluent McLean, Virginia, it’s also heading to auction since it failed to sell after listing for sky-high prices.

Bidding begins on May 15 and closes May 27 with starting bids expected between $5 and 9.9 million, according to Concierge Auctions, which is conducting the sale.

The mansion stands on a prime riverfront perch. Epic Homes USA

It was built in 2008 using a variety of designs. Epic Homes USA

It’s all accessed by a grand entry. Epic Homes USA

Its owner, Hazem Elariny, a bariatric surgeon who performed the Washington area’s first laparoscopic gastric bypass surgery, constructed the limestone residence in 2008 in a mélange of styles ranging from Romanesque to Tuscan.…