Treasure chests are seasonal hunts given to you by the game depending on the season. They restart occasionally every week. These challenges need to be completed and as a reward, you will get a treasure chest.
How to Complete LUCKY SKILLS Treasure Hunt & Find Treasure Chest Forza Horizon 5
So, something you will need to take on this challenge is the Nissan GTR 6th generation. Buy it or if you already have it, take the Nissan and head to the Highway.
On the highway, you need to destroy several guardrails. Basically, just destroy whatever comes your way: trees, fences, sidewalks, lighting, anything.
After a while, you will get a message that the treasure challenge is completed. Then, go to the map and the location of the treasure chest will flash in red.
Transport to the location of the treasure chest and you will easily find it. It is located in the Ville De Las Rana area. Go to the right side of the road.
Pass the bushes and trees that are to the right of the dirt road and on the big rock in front of you is the coffin with treasure. The exact location is shown in the picture above.
When you find the treasure chest go through it and you will get 50,000 CR and 5,000 HP.
And that is all that you have to do for this treasure challenge.