There have been thousands of concepts over the years, some of which have offered us a preview of a production model. In many cases, however, the concept never reached production; it ended its days gathering dust in some warehouse.That’s not necessarily such a bad thing of course; if all concepts reached production, we’d be saddled with the horrific Lagonda SUV unveiled in 2009. But not all concepts are so badly misjudged. There have been dozens over the years that have deserved to succeed. Cars with cutting-edge technology, great looks – or both.

 As a young child (or perhaps even an adult) who hasn’t dreamed of living tree houses? Some structures are built on trees or hung from trees, but some unusual tree house building designs are even grown from trees or built right into a tree. Some people live in trees as a luxury, some to help save the environment and others out of tradition or necessity. Here are ten incredible tree house designs that range from functional to fanciful, sustainable to strange and affordable to incredibly expensive.

 Fairly expensive cars, whose owners, for whatever reasons, have left them.

Flight First Class Recalls stay in expensive hotels.Looking at these pictures, I can understand why the price for first-class ticket exceeds the limit at times.

Everyone needs a personal sanctuary in which to wind down, and this house in suburban Maryland has fostered the sacred on-site in this Tea House by David Jameson Architects
Inspired by the form of a Japanese lantern, the bamboo-embraced Tea House by David Jameson hangs serenely from a steel frame overhead. This glass-and-bronze box serves as the perfect place for a book and hot green tea, a meditation session or a musical recital featuring one of the family’s talented children.

 Cats and cats like to sit and sleep in cardboard boxes, but few people want to put the ugly cardboard box in the middle of his apartment. Canadian Company Loyal Luxe, dealing with pets, came up with beautiful houses for cats. They are made from fully recycled cardboard and can become a favorite animal. There are two models: the "Canadian cabin" and "The Indian wigwam."