Forgotten Citadel

{t}: Add {c}. If there are no counters on Forgotten Citadel and this mana is used to cast a colored
spell, put a color counter on Forgotten Citadel
for each of this spells' colors.
{t}: Add one mana of any color of which there are counters on Forgotten Citadel.
_________________________________________
It has been eons since anybody has laid claim this mysterious citadel. In fact, everybody seems to have forgotten that it even exists.