This area contains some interesting thermal areas. The path from the parking area leads over the river to the boiling Sapphire Pool. Prior to an earthquake in 1959 this was an extremely clear pool around which were sinter deposits shaped like biscuits. Following the earthquake the pool erupted in explosive geyser activity, which washed away the majority of these unusual deposits, leaving Biscuit Basin virtually biscuitlesss! The boardwalk also leads to Jewel Geyser, Shell Geyser, Avoca Spring and Mustard Spring. The circuit is about a ½ mile in length, however there is a further route to Mystic Falls, a beautiful cascade over rugged lava rocks.