MOAB Graveyard is a Special Mission in Bloons Monkey City. In this mission, there are 3 rounds which each correspond to a MOAB-Class Bloon; starting with MOABs, then BFBs, then ZOMGs. Each round consists of spawning a single MOAB-Class Bloon, then a brief period of downtime in between before another one spawns, with the downtime progressively getting longer for each round.
Research MOAB-SHREDR Spikes or MOAB Mauler before tackling this special mission. To beat the highest tier of MOABs, the player needs to have a good amount of MOAB-Class damage and adequate ceramic children cleanup. Using the MOAB-SHREDR Spikes or MOAB Maulers at the front, and using slowdown such as Glue Hose and Arctic Wind, and towers with a lot of pierce that can damage lots of ceramics like Ice Shards and Cluster Bombs all under the range of a Jungle Drums village should be enough to clear the mission.