#1 - Sept. 18, 2014, 3 a.m.
Blizzard Post
Starting with this beta build, all Challenge Mode dungeons are accessible. You can access them either by zoning in manually, or by setting difficulty to Challenge and speaking with Nexus-Lord Donjon Rade (in major cities or your garrison).

Tuning is definitely a work in progress. Some things are brutally hard, bordering on impossible. Some of the mob kill counts are off, and we'd like to hear about that - if you fall short of the kill count without using Invis/Shroud to skip any packs, or if you're completing the kill requirement well before the end of the dungeon, let us know. And of course, Gold/Silver/Bronze times are very much placeholder.

Please use this thread for any feedback and reports of issues you encounter.