One of the most expensive townhouses in London listed Monday for 60 million pounds (about $74 million).

The amenity-packed residence spans six levels, including two that are underground. There, you’ll find a pool that spans 39 feet, a spa, and parking that connects to a hidden roadway.

The eight-bedroom, eight-bath home spans over 14,700 square feet and is in a new residential development called the Chelsea Barracks, located in Belgravia, one of London’s most expensive neighborhoods.  

The development is named after the land it sits upon, a 13-acre site which for 150 years housed regiments from the British Royal Army. The parcel was sold in 2008 by the British Ministry of Defence for $1.3 billion, or a whopping $100 million an acre. The sale price made it one of the largest land transfers in British history and one of the biggest residential real estate transactions in the world.

The site was purchased by the sovereign wealth fund of the State of Qatar in partnership with the Candy Brothers, British developers who later sold their share to the sovereign state’s Qatari Diar Real Estate Company. The company oversaw the development of 290 luxury residences and 130 units of affordable housing on the site.

The mega-development is located less than two miles from Buckingham Palace and a little more than a quarter mile from the River Thames.

According to Richard Oakes, Qatari Diar’s chief sales and marketing officer, the land’s proximity to the river and high water tables underneath required the developer to construct an underground barrier around the construction zone’s perimeter to prevent water from breaching the site.

It’s a pricey feat of engineering that took two years to complete. Oakes told CNBC it was worth the time and money because it unlocked the ability to build downward.

Now the development contains a subterranean world that spans two levels of each of the 13 townhomes. It includes parking spaces interconnected by an underground roadway that leads to a nearby parking garage, creating a stealthy way to enter and exit the homes by car. There is no curbside parking, according to Oakes, so the concealed parking areas are a boon. 

Oakes would not reveal the total cost of the development, but he did tell CNBC the project stands two-thirds complete and has already topped $1.2 billion in residential sales since 2015. And the residences are commanding an impressive price per square foot that averages almost $5,600. 

“We’re absolutely trading on a premium,” said Oakes. “I reckon we’re up 30% premium on local area [residences].”

At about $74 million, the asking price for the townhome amounts to about $5,000 a square foot. Oakes told CNBC he’s “absolutely confident” in the pricing, adding that an apartment unit in the development has already sold for more.

“The release of pent-up demand following the uncertainty of Brexit and the frustration of Covid travel restrictions has boosted activity in London’s 10 million [pound]-plus property market over the last year,” said Tom Bill, head of U.K. residential research at Knight Frank. And even with mortgage rates notably higher, he told CNBC, cash-rich buyers are in a comparatively strong position and the price of 10 million pound-plus inventory has dropped about 12% since its last peak – September 2015 – which will also support demand.

For context, in 2022 London’s 10 million pound-plus super-prime market saw 162 transactions recorded, two more than in 2021, according to data provided by Bill. The number is likely to rise, though, due to a lag in data.

Meanwhile, over the last 12 months since February, the prime central London market saw 560 sales of 5 million pounds plus, with 60 of those transactions occurring in Belgravia. In that same date and price range, the district saw an average price per square foot topping $3,300, compared with just over $3,100 a square foot for prime central London, according to Bill.

Oakes attributes the significant premium achieved at the Chelsea Barracks to a couple of factors, including that the units are all-new construction, which is rare in Belgravia.

He said there’s also value added by concierge services, security, and the community’s residents-only health and wellness center, called the Garrison Club. The club delivers 12,700 square feet of luxe amenities, including a 66-foot swimming pool, gym, steam and sauna rooms, and private training studios.

And high net worth buyers are drawn to a Chelsea Barracks convenience he calls “lock up and leave.”

“Here you can throw the keys at the concierge, go away for a couple of months and come back and your house is warmed,” said Oakes. “You know everything can be done for you.”

Here’s a closer look around — and under — London’s newest $74 million listing, which is being sold fully furnished.

On the first floor of the six-story home, at 3 Whistler Square, is an over 30-foot-long grand reception room. The room has floor-to-ceiling windows with bespoke iron balustrades, which are intricately designed for each townhome.

The entire second floor of the residence is devoted to the primary suite. The 1,600-square-foot area, which can be accessed by a grand staircase or a lift, includes a lobby, handbag wardrobe, two baths and two walk-in closets/dressing rooms.

One floor above the primary suite are four en suite guest bedrooms, and one floor higher is a rooftop terrace.

Now for what’s down below. The first of two lower levels includes a family kitchen and dining area with walk-out access to the garden at the back of the home. This can be achieved on a subterranean level because the rear garden is one level below street grade. Also on this level are two more bedrooms, for staff, and access to a pair of elevators, one for residents, the other for service.

One level deeper is the second underground level, which is the home’s most expansive floor, spanning over 4,700 square feet. This level features a cinema and a wine room plus a separate wine vault.

There’s also a health and wellness area that includes a private 39-foot indoor swimming pool, gym, changing rooms, steam and sauna rooms, plus spa treatment areas. This level also features a 30-foot-wide garage with secured access to an underground roadway for entry and exit.

Across the backyard is a structure called The Mews. The name is a historical reference to stables that were once built behind large city homes to house horses before they were replaced by cars in the early 20th century.

This modern version houses a duplex one-bedroom guest house. While on the surface this second house is separated from the main residence by about 40 feet, hidden deep below the lawn the two homes are very much connected. The subterranean pool level, which is buried two stories directly below the lawn, spans the length of the yard, joining the lowest level of the main house to the lowest level of the guest house.

Oakes told CNBC the sale would be subject to a 15% stamp duty, which would add another $11.1 million in fees. And the buyer should expect to pay a homeowner’s fee, which amounts to about $164,000 per year.