Sanctuary

Why this map is hard

On a normal map you place a tower once and it covers the same piece of track all game. On Sanctuary, every platform moves between rounds, so a perfect spot on round 10 may be useless on round 11. At the same time, four lanes are active every round, so you also have to spread your damage. The platforms are small, which makes big towers and support clusters awkward to fit.

The answer is to rely on towers that do not care where they stand: infinite-range towers, homing attacks, aircraft and map-wide stalls. Short-range towers are a gamble unless they sit on the one platform position you know is good, like the Spike Factory spot by the exit split.

Best towers

• Sniper Monkey: infinite range and no sight blockers, so it works from any platform at any time. It is the backbone of the CHIMPS start.
• Wizard Monkey (2-0-1, later 4-0-2 or 5-0-2): Guided Magic lets its bolts chase bloons wherever they are, and Arcane Blast with Monkey Sense pops camo leads.
• Ninja Monkey (2-0-1, later 4-0-1 or 5-0-1): Seeking Shuriken homes in on targets and pops purples. A Grandmaster with seeking shurikens is a strong late carry.
• Monkey Ace: flies over everything. Sky Shredder (5-x-x) was part of the very first Sanctuary CHIMPS win, alongside Etienne.
• Spike Factory (Perma-Spike or 4-0-2 Spiked Mines): one bottom platform position lets it drop spikes at the split near the exit, where it catches leaks from every lane. Pair it with a Stronger Stimulant Alchemist and a Village.
• Monkey Sub (2-5-0 Sub Commander): the two ponds each fit one water tower, and a Sub Commander is a strong pick there. 0-2-0 Airburst Subs can even handle round 19 early.
• Glue Gunner (Glue Storm) and Ninja (Bloon Sabotage): they slow every bloon on screen, which suits a map where you cannot predict where your towers will be.
• Mortar Monkey: aim it at the intertwining vines in the middle, the only place all bloons pass through.
• Dartling Gunner (0-3-x Hydra Rocket Pods): rockets punch through dense packs. With camo coverage, for example from Etienne's level 8, a 0-3-2 can hit bloons on the opposite lane too.

Best heroes

• Psi: released with this map, and a perfect fit. His attacks reach bloons anywhere, so platform movement does not affect him.
• Etienne: his drones cover the map, his UCAV is strong, and at level 8 he gives camo detection to all your towers.
• Quincy: Quincy plus one Dart Monkey can solo the early CHIMPS rounds up to about round 12.
• Obyn Greenfoot: also works with a Dart start, and his abilities help in later rounds.

Easy and Medium

Use global and homing towers from the start. A Sniper Monkey and a Dart Monkey open well, and Psi or Etienne makes everything easier. Add Guided Magic Wizards and a Spike Factory on the exit-split platform. Get camo detection for round 24 and lead popping for round 28; Night Vision Goggles on a Sniper covers camo.

Hard

For Hard, add a Sky Shredder or a Spectre for blimps, a Glue Storm or Bloon Sabotage for the ceramic rounds, and turn the exit Spike Factory into Spiked Mines or Perma-Spike with a Village and Alchemist beside it.

CHIMPS

1. Rounds 1 to 6: a Dart plus Sniper start works but is tight. Alternatively, Quincy plus a Dart can solo up to around round 12.
2. Rounds 7 to 18: add Snipers, then Subs in the two ponds heading to 0-2-0 Airburst for round 19.
3. Before round 24: camo detection, for example Night Vision Goggles (tier 1 middle) on a Sniper.
4. Before round 28: Full Metal Jacket (tier 1 top) on a Sniper for leads, or a 2-0-1 Wizard.
5. Rounds 30 to 50: place Etienne or Psi if you did not start with them. Start a Spike Factory on the bottom platform that reaches the exit split. Build Guided Magic Wizards or Seeking Ninjas, and Maim MOAB Snipers for blimps.
6. Rounds 50 to 80: Spiked Mines or Perma-Spike with a Stronger Stimulant Alchemist and a Village, a 2-5-0 Sub Commander in a pond, and a Glue Storm or Bloon Sabotage for rushes.
7. Rounds 80 to 100: Sky Shredder or Grandmaster Ninja as the main blimp damage, more Maim MOAB Snipers for DDTs, and stalls saved for 98, 99 and the BAD.

Impoppable

The same plan works, and Banana Farms on platforms do not mind moving. See our Impoppable guide.

Dangerous rounds on this map

• Round 6: the Dart plus Sniper start is barely enough.
• Round 19: a tough early round; Airburst Subs can handle it.
• Round 24: one camo green on one of four lanes.
• Round 28: six leads.
• Round 40: the first MOAB.
• Rounds 63 and 76: ceramic rushes across four lanes.
• Round 78: rainbows, ceramics, a BFB and camo ceramics.
• Round 90: camo regrow fortified leads and three DDTs.
• Rounds 95, 98 and 99: DDTs and fortified blimps.
• Round 100: the BAD.

The BTD6 Master YouTube channel has video guides for Sanctuary.

Frequently asked questions

Do the platforms on Sanctuary move every round?

Yes. They rotate and change position between rounds, and the pattern repeats every 24 rounds.

How do you beat Sanctuary CHIMPS?

Start with Dart and Sniper, or Quincy and a Dart, then use global and homing towers such as Snipers, Guided Magic Wizards and Sky Shredder, with a Spike Factory on the platform that reaches the exit split.

What is the best hero for Sanctuary?

Psi, since his attacks ignore position. Etienne is also excellent thanks to his drones and level 8 camo detection.

Can you put water towers on Sanctuary?

Yes, one in each of the two small ponds on the top platform.

Where should I put a Spike Factory on Sanctuary?

On the bottom platform position that reaches the split near the exit, so its spikes catch leaks from every lane.