When World of Warcraft: Cataclysm launched the Lost City of the Tol'Vir was your gateway to higher level instances. It was the easiest of the end game level 85 instances and could generally be completed by Level 84-85 characters. Now that you most players are geared up, many are going back to check it out on Heroic Mode. To help everyone out check out our Lost City of the Tol'Vir guide, fully updated to cover the heroic mode strategies and abilities.
You can find the full guide here: Lost City of The Tol'Vir