Helorian Halls

{t}: Submerge target land. (Untap it and turn it
upside down. Submerged lands are considered
out of play.)
Once per turn you may tap or untap a
submerged land. If you tap it you may tap it for
any mana or other abilities it can produce.
To the Kro, the dark chambers of Hel were forever
damp with the blood and excrements of salvation.