Fun fact! There are lots of secret chest in Mondstadt! Like on top of this building, there is about two or three + a teleport waypoint to open! Honestly there are tons
All Chests Location in Mondstadt City Guide in Genshin Impact - YouTube
Mondstadt Region Puzzles, Secrets, and Hidden Chests | Genshin Impact - GameA
Mondstadt Region Puzzles, Secrets, and Hidden Chests | Genshin Impact - GameA
Mondstadt City Chest Locations | Genshin Impact
Genshin Impact Luxurious Chest Locations in Mondstadt | Dunia Games
All secret/ hidden chests for the Mondstadt Achievement [Full Guides] Genshin Impact | HoYoLAB