Sanctuary is an Expertmap in Bloons TD 6, introduced in version 26.0. It takes place above an open space with vines and several platforms. The platforms move and/or rotate at the end of each round.
Sanctuary has 2 entrances, which mostly merge together in the middle and split off into 4 exits. There are 6 moving platforms to place towers on, and the only other map to share this mechanic of having platforms that move towers being Geared. There is a statue at the top resembling Psi, the hero released alongside Sanctuary in version 26.0. The platforms move in a cyclic pattern that places all of them in the same spots every 24 rounds. Unusually for an expert map, Sanctuary has no line-of-sight blockers, despite the Psi statue appearing to have a high elevation relative to the rest of the map.
Strategy
Sanctuary is fairly difficult during the early-game due to the moving platforms. The middle part of the track where the paths overlap, however, reduces this map's difficulty during the mid-game and late-game, allowing a variety of strategies to work. Sanctuary is considered to be much easier than the true experts, being around the same difficulty level of Workshop.
There is a precise spot on the bottom-middle platform where Perma-Spike can be placed so that it shoots spikes toward a spot where it can tank all leaking Bloons when paired with a village and a Stronger Stimulant on far targeting. That way, the late game is usually made trivial.
He makes the early game, a difficult part of the game in Sanctuary, much easier with his Spear spell and ability to constantly gain mana. Corvus can save up for many win conditions throughout the mid-game, such as Glaive Lord, Bloon Exclusion Zone, and Perma-Spike. In particular, if Perma-Spike is used, Corvus can remove large amounts of RBE in the late-game with Ancestral Might and Overload and alleviate large of amounts of pressure for Perma-Spike.
The layout of this map makes BEZ very potent and able to easily solo the entire late-game in CHIMPS with proper support, including Alchemist buffs, Relentless Glue, MIB/Glue Storm, Bloon Sabotage, and Overclock. Bloon Area Denial System is a solid Tier 4 upgrade that can do most of the work in saving up for BEZ.