The property's location can't be bettered, but the view from some rooms leaves a bit to be desired.
Buyers seeking a base in one of London's wealthiest neighbourhoods have the chance to purchase an unusual piece of property: a disused London subway station that housed the city's anti-aircraft defences during the second world war.
Brompton Road station is being sold by the Ministry of Defence, which bought the building after it was closed to passengers in the 1930s.
The ministry, which is selling several properties and laying off soldiers in a cost-cutting drive, says the building is "surplus to requirements" and will be put on sale next month.
It is expected to fetch about £20 million (HK$240 million). That buys 28,000 sq ft of aboveground and underground space.
The site includes a station building covered in the distinctive oxblood-coloured tiles of London Underground's Piccadilly Line. The ministry said the interior includes "a drill hall, garages, offices and mess," as well as lift shafts and underground passages - though not the subway tunnels, which remain in use and belong to London's public transport operator.
The station is near the historic Brompton Oratory church and the ritzy Harrods department store. It opened in 1906 but turned out to be too close to other stations to attract many passengers, and was closed in 1934.
In 1936 it was bought by the government and became an army anti-aircraft headquarters, protecting London from German bombers during the Blitz.
The building is still used by the military, housing air and naval units from the University of London and an Air Training Corps squadron.
Simon Hodson of real estate agents Jones Lang LaSalle said that the "prime central London site provides an excellent redevelopment opportunity."
The Old London Underground Company has expressed an interest in buying the station and turning it into a restaurant and entertainment venue.
Brompton Road is one of several abandoned subway stations in London, many of which are derelict.