Casa Batlló, is a building restored by Antoni Gaudí and Josep Maria Jujol, built in the year 1877 and remodelled in the years 1904-1906; located at 43, Passeig de Gràcia (passeig is Catalan for promenade or avenue), part of the Illa de la Discòrdia in the Eixample district of Barcelona, Spain.
This is my favorite tree house picture. It is the loft that you squeeze into. Look close the interior ceiling still as the bark on the wood. So cool. The first time I slept up there I woke up and just stared at the wood for a half hour. I was not even thinking about ... Well never mind.