Thousand Monolith

Whenever a land enters the battlefield under an opponents control, you may tap Thousand Monolith. If you do, tap that land and add {c}{c} to your mana pool. Then put an absorb counter on Thousand Monolith.
At the beginning of your combat phase, if Thousand Monolith has three or more absorb counters on it, transform it.
"Thousands of years it's waited..."