Treehouses appeal to the child in all of us and bring us closer to nature. At one point you probably dreamed of living among the birds in a house nestled on the leafy branches of a towering tree. Whether these structures are tiny shacks clinging to a single bough, unique treetop observatories or sprawling works of art spanning several trees, there’s something magical about treehouses. Here’s a look at 18 of the world’s most stunning treetop structures and the unique stories behind them.