Below

Below is a one-step triumph (1 point): “Investigate the Causeway.”

Overview

A Trivial Mystery from Season of the Lost, in the Ruins of Wrath area of the Shattered Realm. The Causeway is a small cave below the Ruins of Wrath main area. Opening its chest completes the triumph.

How to complete

1. Unlock the Barrier Breach upgrade on your Wayfinder's Compass. The guides say the Ruins of Wrath mysteries are easier to get with the Compass upgrades unlocked.
2. Clear both beacons first so all the signs in the area are active.
3. Go to the island directly behind beacon #1, the Causeway, and descend one floor.
4. Find the Barrier Breach sign near the centre of the room and activate it.
5. Drop down to the path that leads into the cavern, then run through the Awoken barrier on that same floor.
6. Go through the back of the cave. The chest is on the other side of the barrier. Open it to complete the triumph.

Tip: guides place the entry point slightly differently. If one route does not work, try the other descent from the beacon-one island.