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Takachiho's magnificent gorge, with its waterfall, overhanging rocks and sheer walls, was formed over 120,000 years ago by a double volcanic eruption. There's a 1km-long nature trail above the gorge. Alternatively, view it up close from a row boat, though during high season it can be as busy as rush hour. In season, rowers will be mobbed by throngs of hungry ducks.