The Walled Stronghold is a Human outpost near the Hill of the Swarm, not far from Everflow. As with all Human villages, it is the setting for the quest chain for Human character level 20-30 quests after Celestial Vale. It is roughly the middle of the quest chain. Along with Hidden Heroes Village, it is the site of three early level red Legend quests for all characters that give Gems and significant XP.
Using Town Portal or Portal Incense in the 'Ancient Peak' area, among others, will transport the character to Walled Stronghold. Lochmur·Lara, NPC for The Treasure IV, perches atop an island in Ancient Peak area.