Ruins of Sescheron

The wind blows frozen wisps off snowdrifts, where they're caught in the decorated grooves of a cold, iron bridge leading to the broken gates of Sescheron. Where once the sights and sounds of a bustling city could be found, now there are only the distant howls of madmen, glimpses of hungry beasts prowling in shadows, and air thick with the palpable weight of shattered hope.

The Ruins of Ruins of Sescheron are located in Act 3 close the Arreat Crater and were added to Diablo 3 in patch 2.3.

Once the area is cleared player can enter the Elder Santum and the Tomb of King Kanai to obtain Kanai's Cube.

The cube is obtained from the Kanai's Throneroom located on level two of the Ruins of Sescheron in Act Three. This area was added to the game in Patch 2.3, along with the Cube, and is found only in Adventure Mode. Players need not complete a quest or bounty to obtain the Cube; just find the area (which requires some exploration, as it's not marked on the map and the Ruins are large)