Path of Sorrow
The Path of Sorrow is accessible after purchasing and installing the Moon Temple DLC for Heroes of Hammerwatch.
The Path of Sorrow leads up to Brightmoor, where you can find the Mercenary Camp and the Legacy shop. You cannot find any similar structures to The Outlook or The City of Stone.
Things unique to Brightmoor are the Legacy shop where you can spend your Legacy Points, earned through Mercenaries. It also allows access to a graveyard where you can see all perished Mercenaries and being a Mercenary in this area gives you access to the Mercenary Skills and the Master At Arms.
The Moon Temple is a new dungeon to explore. It consists of 3 acts, with each having a respective boss, which resides on the 3rd floor of each act. Completing a run in the Moon Temple will reward the player with the Lunar Shield, which will half the damage you take for 4 hits if beaten on NG+0 and 2 extra hits for each NG+ beaten. It has a cooldown of 2 seconds between hits and recharges every floor.