Head to the Foothill Stale and speak with Mayro who will give you this shrine quest. You will need to look at the picture on the wall and locate the shrine. South of death mountain and southeast of the Foothill Stable you will find the Tah Muhl Shrine. It is at the end of canyon as shown in the picture.
Burn the ivy in the first room with any form of fire you have, either a fire based weapon or a fire arrow, then head to the next room. In this room, burn the ivy on the left.
Enter the room that the key unlocked and open the second treasure chest. Burn all the ivy in the final room and wooden crates and reveal the third treasure chest.
Use stasis on the ramp and head to the altar and collect the spirit orb.