New York real estate is soaring, and there's no better proof than One57.

One of the penthouses in the 1,004-foot-tall residence has officially closed for $100.5 million, making it the most expensive apartment ever sold in NYC and the first to surpass $100 million.

Located on the 89th and 90th floors, the penthouse has 11,000 square feet, six bedrooms, a steam room, a library, and an indoor movie theater.

Residents will also have access to the amenities in the Park Hyatt hotel, which takes up the first 39 floors of the building. But if they don't want to mix with the commoners, One57 owners can also use their own 20,000-square-foot amenities floor, complete with a pool, gym, library, and theater.

And though $100 million may seem like a lot, New York's priciest penthouse will most likely prove to be a savvy investment as more expensive homes continue to go on sale. Already, a tower on 520 Park Avenue has a penthouse on the market for $130 million, and prices are only expected to climb.

The buyer of the megaproperty remains a mystery, as do many of the owners in One57. Of the 26 units sold so far, over half of them are owned by limited-liability corporations and trusts to maintain the owners' privacy.