A man-made geyser of carbon dioxide-charged groundwater on the east bank of the river, about 10 miles south of town. Eruptions are erratic — sometimes once a day, sometimes hours apart — and can throw a column 30 to 40 feet into the air. The travertine terrace around it is stained orange and yellow with iron and sulphur.
The drive in on a dirt road is rougher than the map suggests; high-clearance vehicles are better. There are no facilities and very little shade. Even when the geyser is dormant, the chemistry-set mound and the silence by the river are worth the trip.