Nightmare Zone - OSRS Wiki

The Nightmare Zone is a combat-based minigame located north-west of Yanille bank. Players enter a "dream" to take on bosses they have previously defeated during completed quests. It is run by Dominic Onion, a mage from Lunar Isle. The dreams that make up this minigame take place in an instance of the King Black Dragon Lair.

Nightmare Zone, Old School RuneScape Wiki

Update:Custom Nightmare Zone Rumbles

Kraken, Old School RuneScape Wiki

TIL there's a cap for points in Nightmare Zone : r/2007scape

Oldschool Runescape - Nightmare Zone Melee Guide! Over 100k XP/H

Nightmare Zone lobby cow, Old School RuneScape Wiki

Nightmare Zone, Old School RuneScape Wiki

NMZ Guide AFK training - Public Guides - Vengeance

Nightmare Zone, Old School RuneScape Wiki

The Ultimate AFK Nightmare Zone Guide Old School Runescape

Theoatrix's Nightmare Zone Guide (OSRS)