From Fate/Grand Order Wiki
Lostbelt No.5 - Ancient Titans' Ocean : Atlantis: The Day a God was Shot Down
Atlantis was released on June 15, 2019, on the JP server. Atlantis is the 5rd chapter of the Second Arc, Cosmos in the Lostbelt.
Main Story Clear Reward
- Argonauts: receive 1 copy and it becomes unlocked for Story Summoning.