The Legend Of Zelda: Tears Of The Kingdom offers players a massive world to explore while trying to complete the main quest line. Throughout the world are many NPCs also dealing with their own problems, some being a bit less urgent than others, and it's Link's job to help them out.
After completing the Yunobo Of Goron City main quest, players will find a man standing on a bridge behind the Inn in Goron village. He will want to find the secret hot springs hidden somewhere nearby and will ask Link for help in finding it. While there is the nearby hot spring, Kima is on the hunt for the secret hot springs for a tasty reason.
Checking The Usual Springs
The first hint you'll be given is to head to the usual springs near Goron village to ask anyone there if they know about the location of the secret springs. The usual springs are located southeast of the village and, through some climbing, can be reached fairly quickly. After getting the springs, go to the nearest spring on the left side to meet Grapp, who will tell you about the secret hot spring, and that it's been caved in. After talking with this NPC, enjoy a moment in the hot spring, as standing in its water can heal you for half a heart every second.
Finding The Simmerstone Spring
After getting the hint on where the secret spring is, be sure to stock up with either bomb flowers or rock-fused weapons, as you'll be crushing a lot of rocks. Head to the Gorko Tunnel that is further southeast of the Goron Hot Springs with the red arch above the entrance at coordinates 1992, 2043, and 0424. Enter the tunnel and head to the back, where you'll find that some rocks have caved in and can be destroyed. You can also use the Sage Of Fire's ability to break the rocks without using any resources; it'll just take some extra time.
You'll need to break through multiple layers of rocks to reach the next room and follow the wall to the left to find even more rocks that will need to be destroyed. Continue breaking the rocks to eventually find the secret spring. Watch the following cutscenes to complete the quest and obtain your reward, along with another healing session in the hot spring.