The Korriban Green Endurance Datacron is located in the Vallery of the Dark Lords map on Korriban grants Endurance +2.
The closest Imperial quick travel point is the Sith Academy quick travel point and the closest taxi is the Sith Academy Taxi speeder point - the quicktravel is the farthest left quick travel point on the map and the taxi is the farthest left taxi point on the map.
The Korriban Green datacron is in the Near the Departure Shuttles and is only available to Imperial characters (Republic players must make an Imperial character to unlock this datacron). Finding this datacron will give you a permanent stat boost of Endurance +2 to all your characters on your server, and will unlock the Galactic History 15: Mandalore codex.
Korriban Endurance +2 Datacron (Imperial)
Quicktravel: Sith Academy
Taxi: Sith Academy Taxi
Location: Vallery of the Dark Lords - Near the Departure Shuttles
Codex: Galactic History 15: Mandalore
How to Get the Korriban Green Endurance Datacron
Quick Travel / Taxi / Arrive
This datacron is hidden in the first area where you arrive on Korriban.
Find the Departure Shuttle
While facing away from the temple, take the path that leads to the right past the shooting range and the vendors. Continue following the path to the shuttles. Do not enter the cave you pass.
Find the Hidden Ledge
Once you reach the shuttles, on your left will be an opening to a metal balcony overlooking the valley with two crates and a barrel on it. On the right hand side of the ledge when stepping on to it is an opening to step off the balcony.