The Cavern domain was a deity domain that granted divine spellcasters like clerics with cavernous spells and powers. Their ability to estimate their depth underground and to detect hidden objects improved.
Novice spellcasters were able to use the detect secret doors, darkness, and meld into stone spells. Clerics of some experience could cast Leomund's secure shelter, passwall, and find the path. Those that were masters in this domain had access to maw of stone, earthquake, and imprisonment.