After considerable persuasion, Captain Smith agreed to move Universe to within a hundred meters of "Old Faithful", the largest geyser on the dayside.

In the beginning of the 20th century, the largest geyser ever known, the Waimangu Geyser existed in this zone.

This complement of features includes the most famous geyser in the park, Old Faithful Geyser, as well as four other predictable large geysers.

An immensely large geyser shoots within a vertical shaft.

Old Faithful is not the largest or most regular geyser in the park.

Some time preceding 1925, the two must have been eventually become connected at some depth and they have since performed as one very large geyser.

Echinus is the largest acid-water geyser in the world.

In Florence there was a predilection for having many small thin elegant jets of water, even when there was enough water to have a large geyser.

Two days before Deka's evening visit the Apprentice Aquamancer experimented with superheated steam jetting from one of the largest geysers in the valley.

"Old Faithful erupts more frequently than any of the other big geysers, although it is not the largest or most regular geyser," says the Yellowstone Association leaflet.