The oval birdís nest treehouse is 12ft (3.6m) tall and 9ft
(2.7m) in diameter reached by a spiralling staircase 18ft (5.5m) tall. The
treehouse is owned by the town of Kamishihoro for
the people of Hokkaido. Takashi built his first treehouse in
1993, on a piece of land he rented in Tokyo; since then, he has built 25 more,
most of them for schools.