The Ring of Sacred Volcanoes (often called "The Ring" for short) was an area in the north-eastern part of the Beyond. It is a chain made of five volcanoes, in which the Ember of Hoole travels around. This is also where the dire wolves of the Sacred Watch live, guarding the ember from graymalkins, owls who wish to use the ember for evil purposes. It was later destroyed by an earthquake in Spirit Wolf, but reappeared in the Bears of the Ice series.
The volcano Dunmore was named after Dunmore MacDuncan, the second Fengo of the Sacred Watch. Coryn mentions that it is the volcano that spewed the first bonk coals he ever caught on the fly.
It is unknown who this volcano was named after.
The volcano Kiel is named after a location in the Northern Kingdoms, which is possibly named after an unmentioned historical figure named Kiel.
The volcano Stormfast is named after the mate of the original Fengo who was called Stormfast and died during the journey to the Beyond. It's also possible that this name is connected to the Stormfast Island, the location where Ezylryb was hatched and raised.