Hallowfall

Hallowfall is a subterranean zone in Khaz Algar introduced in World of Warcraft: The War Within. Located below the Ringing Deeps and above Azj-Kahet, Hallowfall is an enormous cavern, bordered by an endless underground sea. A massive crystal "sun" lodged into the cavern ceiling provides light, warmth, and growth for vegetation, creating a bright and lush environment reminiscent of the surface world.

Hallowfall is inhabited by a civilization of humans of the Arathi tribe. At an unknown point in time, some Arathi left the Empire of Arathor and created their own kingdom across the sea. Another group in turn splintered from that kingdom and settled in Hallowfall after receiving a vision of a falling star centuries ago. From their capital of Mereldar, these Light-worshipping, martial Arathi use their holy fire-powered airships to travel to high plateaus throughout the cavern and fight a near-constant battle against monsters emerging from the underground sea as well as from swarms of nerubians from Azj-Kahet. The nerubians have thus far been held back from invading Arathi lands, but the outnumbered Arathi now face division within their own ranks. In addition, the crystal sun, whose light was once steady and reliable, now randomly cycles into a Void state without warning for periods of time, bringing with it new hostile creatures and plunging the Arathi into darkness save for the areas where they have built beacons of Light.

• Hallowfall's crystal is not related to the Sword of Sargeras. Many see it as the sword's buried tip at first glance.
• Hallowfall appears to be inspired by the trope commonly seen in . Many Hollow Earth stories portray a lush underground world sustained by an inner sun, often also featuring a subterranean ocean and lost civilizations of ancient humans.