What are monkitropolis?

Some articles on monkitropolis:

Super Monkey Ball Adventure - Plot
... On Jungle Island, Aiai meets Prince AbeABE of Monkitropolis and Princess DeeDee of the second proportion of Monkitropolis, the underwater city of Kongri-la ... before Aiai has completed quests by monkeys around Kongri-la and Monkitropolis, The two cities both blame each other for their problems in their cities ...