The Breakers is probably the largest of the mansions along The Cliff Walk in Newport Rhode Island. It has 70 rooms with approximately 65,000 square feet. It reportedly cost $7 million to build in 1895. That's about $150 million today. That works out to about $2,300 per square feet. It was built for Cornelius Vanderbilt II. Among other things, Vanderbilt is the great grandfather of CNN's Anderson Cooper. He also had a stroke the year after the Breakers was completed. You can read a short article about him here.What does $2,300 per square feet buy you. Something like this next picture which is the mansion library. According to the back of the card, the Library is "paneled with Circassian walnut stamped in gold and decorated with bas-relief carvings in High Renaissance style". I have no idea (and neither does Wikipedia) what Circassian walnut is but it's got to be something special.
The mansion is a National Historic Landmark and has been owned and operated by the Preservation Society of Newport County since 1948. It is open to tours by the public during summer months. If I ever get to Newport this is one of the places I really want to visit.