One of the largest apartments in London, a massive 7,100-square-foot penthouse in a historic mansion on Hyde Park, has been listed for sale by Christie’s International Real Estate affiliate Strutt & Parker for about $55 million.

Spanning the entire top floor of a massive Victorian mansion formerly known as Wellington Court, the sprawling six-bedroom, six bath penthouse also features six rooftop terraces with views over Hyde Park and Knightsbridge. The penthouse was listed briefly before being offered as a rental at $25,000 per month.

The building is located directly beside One Hyde Park, home to the most expensive apartment in the world, and the Bulgari Hotel, putting it firmly in London’s most desirable real estate position. As we noted recently, London is now the world’s most expensive city.

A private elevator to the apartment, a 24-hour concierge and private parking within a central courtyard, well protected from the street are all included in the unit. The posh pad, completely renovated by a top architect, also comes complete with a world-class interior design scheme befitting a billionaire owner.

Soaring ceilings, rich leather and wood paneling including some from rare trees, massive windows, an impressive library, designer chef’s kitchen, luxe marble baths, a private gymnasium and massage room, a dining room with a built-in Italian bespoke black glass and mirrored bar and Swarovski crystal detailing, and indoor and outdoor fireplaces are other highlights of the property.