TerraRealms: The Discovery - Episode I (2001)

TerraRealms: The Discovery is a 1st person, point-and-click adventure game strongly influenced by games like Myst. You start in a dark forest with towering trees and a path. As you wander in different directions, you come upon a few caves. In one of them is a tray containing triangular-shaped pieces. By exploring further, find the clue needed to solve the puzzle in the tray. When solved, something else happens. And so the gameplay continues.