Here in scripture is the lake of fire mentioned:
NKJV Revelation 20:13-14. The sea gave up the dead who were in it, and Death and Hades delivered up the dead who were in them. And they were judged, each one according to his works. Then Death and Hades were cast into the lake of fire. This is the second death.
NKJV Revelation 21:8. But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death.”
Brimstone is an old-fashioned name for sulfur, a chemical that can be found in volcanoes.
When molten magma comes to the earth’s surface, it turns into lava, which dries. Molten magma beneath the earth’s surface continues to burn. This is the only lake of fire on earth!
During a spiritual battle in which Father God had fought for me, I asked Him about this and He revealed to me that this molten magma is indeed the lake of fire.