Archvale

Trial monuments can be found scattered all over the world. The first one can be found after the Maxilla boss fight near the start.

Enter the trial arena
Activate it by standing on the stone plate
Avoid the red projectiles while running over the blue gems
Once you've completed three rounds the trial ends, rewarding you with a chest.

Trials are stone monuments with a Blue Gem floating above them, when you find one, approach the Gem and press A to enter an instance. In the instance you must step on the stone switch in the center of the floor to activate the trial. Once activated, the goal is to constantly grab the blue gem to proceed through 3 waves of attacks and receive the reward of a Badge. During the waves if you are attacked even once, the wave will reset. If you get to the next wave and then get hit, you will reset to the beginning of that wave. The Achievement will unlock upon finishing the 3rd Wave.