The Plaguelands: The Scarlet Enclave, often shortened to Scarlet Enclave (also called the Scarlet Lands) is the name of the starting area for all death knight players in World of Warcraft: Wrath of the Lich King.
The Enclave is an instanced area set in the southeastern corner of the Eastern Plaguelands and encompasses the city of Tyr's Hand, the villages of New Avalon and Havenshire, and a small region around Light's Hope Chapel.
The death knights start at a necropolis called Acherus: The Ebon Hold. The towns, New Avalon and Havenshire, are pristine and untouched by death, and it is the duty of the death knight - who at first starts in the service of the Lich King - to lay waste to both towns and participate in a final battle for Light's Hope Chapel before they can join the "main world".
The Scarlet Enclave is separated based on faction: Alliance players will not see Horde ones while inside the instanced area, and vice versa. However, once the death knight leaves the instanced area and returns to the "main world", both sides will be able to see one another normally.
The entire region (with the exception of Acherus, Death's Breach, Tyr's Hand and everything on the western side of the mountains beneath Acherus) is marked as Ruins of the Scarlet Enclave in the main Eastern Plaguelands, and is accessible from Tyr's Hand or the cave in the Noxious Glade (which was used to reach the main battlefield for The Light of Dawn).
Major Towns and Points
Where to start? Well, somebody would say all the way back to Warcraft I (aka Warcraft: Orcs & Humans or the First War), or maybe Warcraft II (aka Tides of Darkness or the Second War up to and including Wrath of the Lich King, Warcraft III is the best place to start. Also, this game then elicits more interesting questions. For instance, how Illidan Stormrage became so hated or where the Scourge started. You will learn all the history and geography of the Warcraft with our help and dedication.