Botryoidal Spring is a fountain-type geyser in Yellowstone National Park’s Lower Geyser Basin, part of the White Creek Group with A-0 Geyser and Spindle Geyser. Named for the grape-like geyserite formations around its vent, it was once considered a hot spring until seismic activity in 1996 turned it into an active geyser. Its eruptions usually last about a minute and recur every 3 to 5 minutes, sending water about 10 feet high. They begin abruptly with a broad, moderately noisy burst, sometimes marked by a blue bubble from rising steam, then subside into smaller bursting before the pool quickly grows quiet again.