When it comes to private, single-family residences, a home called Antilia, located in Mumbai, is king. Completed in 2010, it is worth an estimated $1 billion – $2 billion. It is 27 stories and 570 feet tall (as a comparison, the Gateway Arch in St. Louis is 630 feet and the Seattle Space Needle is 605 feet tall). Since many floors have double or more the normal ceiling height it is equivalent to a 40 story building in height.

It was built by Mukesh Ambani, head of Reliance Industries Limited, a large Indian conglomerate. He is worth $27 billion which makes him the wealthiest man in India. Mr. Ambani, his wife, and three children reside in the house (when they aren’t away at college).

Some facts about the home:

• It is named after the phantom island of Antillia that at one time was supposed to lie off the coast of Portugal. It’s also referred to as the Isle of the Seven Cities. Read more about the legend of the phantom island here.

• Antilia has parking spaces for 168 cars and three helipads on the roof.

• It contains a 50 seat cinema

• There are nine elevators

• A staff of about 600 serves the family and keeps up the residence.

• Antilia has multiple swimming pools, a spa, and a health/yoga studio,

• There are four levels of hanging gardens.

• It’s designed to survive a magnitude 8 earthquake

• At 400,000 square feet and a value as much as $2 billion, Antilia is both the largest private, single family residence in the world as well as the most expensive. (Note that governmental palaces and homes like Buckingham Palace and the White House are not in the running.)

Here are some diagrams and pictures: