Relics are typical collectibles in Far Cry 3. They are shown with a symbol on your world map.

There are 120 of them in total. Only 60 are required for this trophy and there is no need to collect the rest. You can keep track of your progress in the Handbook tab of the pause menu.

To reveal all their locations you must activate all of the radio towers and buy the item maps from a shop. All maps together cost $4000. Once the maps are bought you can zoom in on your in-game world map and see the exact locations.