After the Kashuan Keep was built, the King of Kashuan worried that people would try and steal it. So he built a door and three keys. Unless one was a member of the Kashuan royal family, it was impossible to open the door without a key.
The three keys were built from friendship, love, and wonder. The keys built from friendship and love soon broke, but the one built from wonder never did, and it was this key that became the Goddess's Bell. Pleased with this key, the king ordered that it should be hidden in a cavern of snow. It was, and it was guarded by an Adamantoise.