Horai Mountain (宝来山 Hōraizan?), also known locally as Treasure Mountain, was where the Pot of Liberation was kept after it ended up in Japan and out of the hands of the Musk Dynasty. It was destroyed during Ranma Saotome's battle with Herb.
Although accessible by a suspension bridge, the mountainside was very steep, making climbing difficult. The summit was wooded and inhabited by monkeys so fierce that they were called monsters, apparently attacking and killing anyone who climbed the mountain. The pot was housed in a massive boulder shaped like a kettle which held back the springs below it at the very peak.
After Herb had been trapped in his female form by water from the Pail of Preservation, he traveled to Japan in search of it, learning from Cologne that it was at Horai Mountain. Following Ranma's confrontation with Herb and his getting splashed with water from the pail to get trapped in his female form, Cologne gave her the map to the mountain. It was entrusted to Mousse, who along with Ryoga Hibiki, accompanied Ranma with the intent of trying of locking themselves in their normal forms with the pail. However Mousse lost the map and their funds thanks to his terrible eyesight, and the three had to temporarily work and stay at the Hotel Imozuru. However after Herb herself briefly stopped there, they were able to follow her, Mint and Lime to the mountain.
Herb and her companions arrived first and quickly ascended the mountain thanks to their animal abilities. When they arrived at the summit, they were attacked by a horde of monkeys but forced them to back off, and the monkeys were stopped from attacking again when they sensed the three's predatory animal natures. Herb followed up by firing a ki blast at them to drive them off. After a tough climb, Ranma and the other two gained the summit, but the monkeys, sensing the weak nature of their cursed forms, got into a brawl with them. After a search for the pot by using the pail, Herb stopped to rest while Mint and Lime continued. Their three pursuers came across them, but Ranma was knocked out as Ryoga and Mint went after the pail. They succeeded in defeating Lime and Mint and splashed themselves with the pail, but got trapped in their cursed forms.
However the pail then pointed the way to the pot, which Herb also noticed when trailing the three as the pot began to glow despite being hidden behind rock. A boulder thrown by Mint bought time for Herb to blast off the tip of the spout of the kettle-shaped boulder. The trapped water was released and boiled by the pot, allowing Herb to become a man again. During the ensuing fight with Ranma the peak and boulder were sliced by Herb's "Flying Sword of the Dragon", with the boulder sent rolling. Lime and Mint were able to stop it, but Ryoga and Mousse then snatched the pot. However they were caught and nearly lost control of the pot, but were saved when Ranma's Hiryū Shōten Ha caught all four in the resulting tornado. Ryoga, who had the pot, was able to shake off Lime and they fell into a river. The pot boiled the waters, allowing Ryoga and Mousse to return to normal.
But when they tried to get the pot to Ranma, an earthquake tore the ground open and the pot fell into it. Ryoga dragged Lime into the chasm before it could close up to briefly hold it open and was able to retrieve the pot, tunneling through the ground with the Bakusai Tenketsu and releasing a geyser of boiling water. Ranma released another Hiryū Shōten Ha to suck in the water from the geyser, returning to normal and hitting Herb with a revised version, the Dragon's Descending Crashing Wave. This knocked Herb out, preventing him from reacting when another earthquake triggered by the battle erupted. Herb fell into the resulting crevasse, but was saved by Ranma and the entire group was able to escape the subsequent destruction of the mountain. Both the Pail of Preservation and Pot of Liberation were apparently lost as well.
Back in Furinkan it was reported on the news that Horai Mountain had been destroyed, on the same day that Ranma, Ryoga and Mousse returned, soaking in the Tendo Dojo furo where they were found by Akane Tendo.