Way to Go, Garri-Son
Finish all the Garrisons
There are a total of 13 Garrisons in the game. A Garrison is essentially a base filled with enemies (and occasionally a Blood Dragon.) Clearing a Garrison allows you to use it as a fast travel point and grants access to sidequests, vending machines and weapon attachments.

To liberate a Garrison, you must kill every enemy within, as well as any Blood Dragons that are housed inside. The best way to go about liberating a Garrison is to do it stealthily by using takedowns and your bow. Aim to disable the alarms first by approaching one and holding Square , which will prevent reinforcements from being called in the event that you are discovered. Liberating a Garrison without an alarm being set off will provide you with an XP bonus, and doing so without being discovered at all will grant an even bigger bonus.