I recently received a spoof email showing a multitude of weird houses which unfortunately all turned out to be "photoshopped" pictures but it did start me thinking about unusual buildings around the world therefore, for you entertainment, I have compiled this list of 6 of the best.

Space Ship House 1408 Palisades Road, Signal Mountain, Chattanooga Tennessee  USA

The Space Ship House is one of Chattanooga's  best known residences. It is a the three-level flying saucer-shape house.
It is larger than it appears from the outside being 1954 square feet. It was built in 1970 by a Mr King a local builder who in a 1973 newspaper story, called the Space House "the House of the 21st Century."  He believed it would revolutionize the building industry in Chattanooga."  Not counting its unique appearance, the Space House had several unique features. The support legs provide plumbing and electrical connections, the house is built of steel and concrete.  According to old newspaper stories, Mr. King and his family envisioned building similar houses around the nation, but the cost became prohibitive. So the prototype mothership became a one-of-a-kind Chattanooga structure.
It is currently for sale but so far, it's only drawn 'local interest' on Earth.

Driving north from the Naha airport towards Okinawa you can’t miss this original seafood restaurant seating up to 120 people.  It is sure to bring back memories of childhood when you wanted a tree house yourself but don’t expect to see a lot of kids at this tree house, Naha Harbor Diner is known for being romantic, and quiet.
It lies at the very top of a huge Gajumaru tree about 20 feet above the ground. Sadly, that is not a real Gajumaru tree, its actually concrete.

Ripley’s Believe it or Not Building 3326 West Highway 76 Branson Missouri  USA

Most people think California has had the worst earthquake in history, when actually Missouri holds the record. In 1812 an earthquake measuring more than 8.0 on the Richter Scale occurred at New Madrid, Missouri. This earthquake made the Mississippi River run backwards for three days and made Church bells ring In Philadelphia! The Ripley’s Believe It or Not building was built to commemorate that quake. It has become one of the most photographed buildings In the world!

Al Khazneh, the ‘Treasury’ of Petra Edom Mountains, Arabah, Ma’an Governorate, Jordan

The red rock city of Petra, dating back to approx 65BC, is located at the end of a ¾ mile trek (on foot, camel or horse) through a Siq, a narrow rock fissure in the cliffs.
While the Treasury’s façade, standing several stories high is very impressive, the purpose of this monument is a puzzle. Some say that it was a tomb, although no inscriptions or crypts have been discovered. Others suggest that it was a tax house for passing camel caravans, but historians doubt that many camel caravans came into Petra, as most of them travelled on the King's Highway many miles away.  It may even have been a library similar to that found at Ephesis in Turkey with a central reading room hewn out of the solid rock and smaller ante-chambers to contain scrolls.  One thing is certain, the Treasury Monument was built to impress as it grabs the attention of every visitor as soon as they exit the Siq to enter the city. 

Upside Down House Centre for Education and Regional Promotion Szymbark Kaszuby, Poland

This Upside Down House was built by Daniel Czapiewski, a Polish businessman in the tiny village of Szymbark. 
The workers, as well as the many thousands of tourists who have entered through it’s attic window, complained of mild seasickness and dizziness after just a few minutes, most likely due to the body’s need to straighten out its equilibrium. It was built as an artistic statement about the end of the Communist era.  Indeed, many citizens of Poland felt as if their entire world had turned upside down after the fall of the Communist regime and the establishment of a democratically elected government.

Dar al-Hadschar Palace Dar al Hajar Imam Yahya's rock palace Wadi Dhar Valley Yemen

The green Wadi Dhar is famous for the Dar al-Hadschar Palace (Rock House), which was erected on a rock standing in the valley. The Yemenis like to come with their families to this vantage point overlooking the beautiful Wadi Dhar for wedding receptions. On Fridays you can watch the traditional dances of all male guests invited to the wedding.