Hall City Cave

Hall City Cave is a limestone cavern near Hayfork in Northern California that penetrates about 200 yards into the mountainside. The passage terminates at a large underground pool with a deep vertical shaft dropping below the water surface.

The cave was first documented during an exploration in 1903, which resulted in finding a significant fossil from the Permian period. This early expedition contributed to understanding the geological history of the area.

This location held spiritual significance for the Native American groups who lived in the surrounding lands and incorporated it into their sacred practices.

The cave stays cold and constant year-round at around 9 to 10 degrees Celsius, so bring warm layers regardless of the season. Specialized climbing and safety equipment is necessary for exploring deeper sections, particularly when approaching the underground pool.

A mysterious stone ring measuring roughly 2 feet (60 cm) across rests beneath the water surface, positioned directly above the deepest part of the cave. The purpose and origin of this object remain unclear to this day.

Location: California

GPS coordinates: 40.41140,-123.01200

Latest update: December 13, 2025 17:02