Goroku Onsen Gorokukan is a secluded single-inn hot spring located in Honjo, Maniwa City, Okayama Prefecture. The spring is believed to have been discovered in the early Edo period. The name 'Goroku' has several origin theories: one suggests it comes from local farmers who gathered here to soothe their fatigue after rice planting season in May and June, while another attributes it to the year-round greenery maintained by the geothermal heat of the spring. The charming building dates back to the Meiji era and sits atop impressive stone walls built cooperatively by villagers of that time.

The water is classified as alkaline simple hot spring (low-tension alkaline hot spring) with a pH of 9.1. The source temperature is a mild 34.2 degrees Celsius with a flow rate of 30.5 liters per minute. The most remarkable feature is the foot-gushing spring, where hot spring water rises directly through cracks in the natural bedrock at the bottom of the bathing pool. This phenomenon exists at only 50 to 60 locations throughout Japan, making it exceptionally rare. The water is rich in metasilicic acid and renowned for its skin-beautifying effects. The spring is free-flowing with no added water, though partial heating is applied.

The bathing facilities operate exclusively on a private reservation basis, with both indoor and outdoor baths available. Day-trip bathing costs 500 yen for adults and 300 yen for children, available from 10:00 to 16:00. Overnight stays range from 12,000 to 14,000 yen per person with two meals, featuring the inn''s specialty: softshell turtle cuisine raised in the hot spring water. The inn is closed every Wednesday.