Hotel Lambert, Paris

Taken from the boat.

A member of the Qatari ruling family bought the Hotel Lambert mansion from the Rothschild banking family in 2007, in a deal valuing the Parisian landmark at around 80 million euros ($111 million).

Hotel Lambert lies on the Ile St Louis, an exclusive island in the middle of the River Seine, a bridge away from the Notre Dame cathedral. The mansion's previous owner, Baron Guy de Rothschild, died earlier that year at the age of 98.