Lost Documents is a quest in Unturned 3. It is obtained from Colonel Jourdan. 

Overview: 

Colonel Jourdan has some important documents that were left behind during the evacuation from Marseille. Find the documents for him.

Walkthrough:

1. Talk to Colonel Jourdan.
2. Go to Marseille. You will need a gasmask and a good amount of filters depending on how much time you spend in the deadzone. 
3. Find the sandy red-colored building. It is located near the watchtower. Head up to the second floor and find the room with the computer screens. The documents will be on the floor under the table. 
4. Head back to the safezone and meet up with Colonel Jourdan.