The golden cage

From Legonia

The term "golden cage" in legonian mythology refers to the secret prison of the demongod Magmaros, which is told to be located deep under the surface and the realm of Onyxo.

It's described as giant cave with a magma lake and a small rock island in the middle. On the island, Magmaros is bound for eternity while 777 imps are swimming in the lake. The cave is closed by massive rock and covered with molten gold. Elemental ghosts of the element fire and earth are guarding its crust so that nobody will ever dig a tunnel to it.

Due to the legend, the god Onyxo created the prison and beatened Magmaros in the ancient war.