Life's a Beach for Celebrities and Their Real Estate!

The "King of All Media" Howard Stern is about to become the King of the Hamptons - construction is underway on his castle, a 16-thousand square foot mega-mansion!

He's building eight bedrooms, 12 bathrooms, a bowling alley and a wine cellar, and for all of it he plunked down a whopping $20 million - just for the vacant lot!

And there's no better way to put rumors of marital strife to rest than buying an $18 million love nest - just ask Howard's neighbors Billy Joel and wife Katie Lee.

"We just closed," Katie told "Extra" of their gigantic home.

"There's no furniture. There's nothing in it. It needs work!" admitted Billy.

Kelsey Grammer is also building big - he's got a 5-thousand square foot oceanfront home!

It's got five bedrooms and six bathrooms.

"I love the Hamptons in the summer," said Kelsey.

And so does Billy's ex Christie Brinkley - she just took her $8 million cottage off the market because she's staying put for the summer!

"We're partying, Hamptons style!" joked Christie.

Further down the coast, Matt Damon is building a huge Miami mansion.

Matt bought the property next door to his $10.3 million oceanfront Miami beach pad, leveled it and is reportedly going to build tennis courts and a pool!

Jennifer Aniston knows that in California, the best place for the summer is in Malibu - even if it's just a rental.

Ashley Olsen is renting, too - plunking down $22,500 a month for a fully-furnished beachfront property.

But if you're on a budget you can park your trailer next to Matthew McConaughey's Airstream!

His is just $50 a day and it's still got that ocean view.