Other Anthem Guides:
All Overlook Locations Guide (Trailblazer Collectible Challenge)
There are a total of 10 Overlook locations to find in Anthem. There is one Overlook in each of the 10 zones in Bastion. The Overlooks are small boxes you open which than pan to a nice view over a specific part of the zone.
You need to find all 10 of the Overlooks to complete the "Trailblazer" challenge. That challenge is one of the required ones you need to complete in order to get the "No Stone Unturned" trophy / achievement.
None of the Overlooks are missable and you can get them at any point in the game. You can track which ones you have found already by going to the "Exploration" challenge section and then looking for "Trailblazer".