In Far Cry 6, you’ll encounter a couple of checkpoints all around the map.
They’re basically checkpoints for Castillo’s army and taking over them will grant you a fast travel spot.
Here’s how you can capture a checkpoint.
Destroy the FND Billboard and clear the camp
You basically will encounter a group of soldiers in the checkpoint. Clear them out first. Watch out for backups that might come.
When the area is secure, destroy the FND billboard which has Castillo’s face on it.
Shoot the barrel beside it to burn the billboard.
Once the billboard is down, the checkpoint is yours and you can use it as a fast travel point on the map.