Feel the burn
Goron City is a scorching hot location, but there are plenty of friendly Gorons who need Link’s help. East Restaurant Cave is not too far from the town, though it is easy to miss, as it is hidden out of view. Upon entering the cave, you’ll find that it initially appears inconspicuous. However, it does hold a few secrets that make it worth exploring
If you’re curious about how to reach and enter the East Restaurant Cave in Tears of the Kingdom, read on.

How to get to East Restaurant Cave in Tears of the Kingdom
From Goron City, stick a fan onto one of the carts on the railway near the settlement’s entrance. The coordinates are: 1610, 2396, 0396. Activate the cart and let it take Link southward. When the cart reaches the end of the railway line, continue the journey on foot by following the path that runs past the Southern Mine.

The path eventually reaches a cave entrance which has a railway track running out of it. The entrance is at the following coordinates: 1845, 1713, 0290. It’s scorching hot in there, so leave your wooden weapons and shields at home. Link should also throw on some flame-resistant armor such as the Flamebreaker set.

What to do in East Restaurant Cave in Tears of the Kingdom
After entering the cave, Link will find a large river of lava obstructing him. To get over it, head right and jump onto the stone platform jutting from the wall. This will allow you to leap to the island in the river of lava. From here, you can leap to the other side of the pool of lava.

Near the ledge, you’ll find a spot on the wall with a breakable rock. Smash through it to claim a Ruby in a treasure chest. You’ll also spot a cart blocking a hole. Remove the cart and crawl in. There’ll be another wall with breakable rocks waiting for you. Smash it to discover the Bubbulfrog, then kill the frog to acquire its gem. Lastly, head back to the ledge facing the lava river. Go in the opposite direction of the river, and you’ll find about five pieces of Rock Roast.
It is not a waste of time to find East Restaurant Cave, as Bubbul Gems can be given to Koltin in exchange for prizes. Link can’t munch on Rock Roast but the item is required for a few quests, including “Rock Roast or Bust”.