树屋曾是人们躲避危险的临时住所，但随着时代的进步，树屋的样式和用途也在不断改进和变革。从儿童玩耍的好去处，到现在，越来越多的成年人会选择在世界各地新奇、古怪、有大胆设计的树屋中住上几晚，重拾接近自然的体验。甚至还有些大型公司选择建造树屋办公楼给员工提供别样的思考和放松空间。

The noble tree house – all natural materials, sturdy construction, aloof from the troubles of the world. In a more dangerous time in human history, their position above the ground would protect the dweller against environmental difficulties and possible predators. As modern construction has improved, these arboreal residences have become less of a practical dwelling and more of a children's novelty - a secret den erected in many a back garden. But now, these fun shelters are appealing to adults too and many are booking themselves in for a few nights among the treetops.

These tree house hotels can be found From Europe to Australia. Best of all, they come in a variety of interesting designs! From the traditional 'four walls and a roof' habitation, such as at TreeHouse Point, in Washington, North America, to the more artistic Nothofagus Hotel in Chilean Patagonia, whose twelve-sided walls make it look like a beehive. If that doesn't appeal, how about a tree pod?

The Free Spirit Spheres resort on Vancouver Island in Canada allows guests to stay in one of three yellow spheres, which are suspended from trees. The company was founded in 1998 by Tom Chudleigh, who hand built the pods from cedar wood and fibre glass, and then added fixtures and fittings. Not only are they as safe as houses, they're popular! Visitor numbers have probably doubled in the past five years, Mr Chudleigh tells the BBC.

Digs which are original seem to be a big draw. In Sweden, at the Treehotel, numbers have also risen. "In 2010, we had four rooms and around 1,500 guests a year. Today we have seven rooms and nearly 5,000 guests," Kent Lindvall explains. Mr Lindvall co-owns the Treehotel with his wife Britta Lindvall. Each of the domiciles there was designed by an architect, who was asked to make use of the light and surroundings. Their abodes include a mirrored cube, a bird's nest and a UFO.

And how about an office? Microsoft, hoping to give its employees thinking space, has commissioned a three-building structure from Pete Nelson, tree house book author and designer and builder of tree houses. "Studies show people can work better in nature. They are more productive," says Mr Nelson.

If you've no head for heights, then maybe a tree house getaway isn't going to be your home away from home. But the sense of adventure, the novelty of the setting and the opportunity to return to nature has given an increasing number of tree house-staying adults something to write home about.