Watchstones in Path of Exile (POE) are no longer obtainable in the current game version. The Atlas system underwent a significant rework in the Siege of the Atlas expansion (February 2022), replacing Watchstones with Voidstones.
Here’s a quick rundown of the current Atlas system:
Voidstones: These function similarly to Watchstones, increasing the tier of your maps and unlocking access to harder challenges and better rewards. There are four Voidstones to acquire.
Atlas Passives: The Atlas skill tree offers various passive points that influence map mechanics, rewards, and difficulty.