Misko's Treasure of Awakening III - The Legend of Zelda: Tears of the Kingdom Database

In-game Description

Obtained from the stone tablet inside the Coliseum Ruins Cave.

The message from the bandit Misko said, “On Hyrule Ridge, in Ludfo’s land, ruins sleep beneath the towering mushroom trees. Connect the southern column’s midday shadow to the northern. At the shadow’s
center, the way to my treasure will open.”

Solve the riddle to find the treasure.

You need to head to Thundra Plateau. To open the cave entrance, you must wait till Noon (12 to 1). During that time period, extend the shadow of the southernmost pillar so the shadow touches the northernmost pillar.

You can do this by cutting down 4 (or more) of the nearby mushroom trees and using Ultrahand to combine the tree logs into one long one. Then drag the combined tree length-wise so it’s near the ground, like in the screenshot (must view in Database!).