The Voss Purple Mastery Datacron is located in the Voss-Ka map on Voss grants Mastery +4 (it used to grant Willpower +4 before the stats changed).
The closest Republic quick travel point is the Ken-La Outpost quick travel point and the closest taxi is the Ken-La Outpost Skyhopper speeder point, both in the top left of the map.
The closest Imperial quick travel point is the Fort Kodentha quick travel point and the closest taxi is the Fort Kodentha Skyhopper speeder point, both in the bottom left of the map.
The Voss Purple datacron is in the Circle of Columns and is available to both Imperial and Republic players. Finding this datacron will give you a permanent stat boost of Mastery +4 to all your characters on your server, and will unlock the Galactic History 77: A Return to the Unknown Regions codex.
Voss Mastery +4 Datacron (Both Factions)
Quicktravel: Ken-La Outpost / Fort Kodentha
Taxi: Ken-La Outpost Skyhopper / Fort Kodentha Skyhopper
Location: Voss-Ka - Circle of Columns
Difficulty: Easy - but time consuming
Codex: Galactic History 77: A Return to the Unknown Regions
How to Get the Voss Purple Mastery Datacron
You can see this purple Datacron while travelling on the Voss speeder, but you’ll need to find the secret path that starts far away to get to it. There is no way to stop or pause the taxi.
You may also see it while exploring the capital city of Voss-Ka, and be tempted to jump down to it. If you do, even if you are a careful rock jumper, you will automatically die once you get to a certain point down the mountains, so you’ll need to find another path to reach the purple datacron.
Quick Travel / Taxi
Find the Hill
Follow the Rock Path
At one point the path looks like a dead end, back track a bit and start jumping up again.
Jump Up the Rocks
Eventually you will reach the broken circle of columns with the datacron.