Blizzard just casually gave players the key to one of WoW's classic dungeons—the original four-wing Scarlet Monastery—in a Halloween event

pcgamer.com:

World of Warcraft's shaken up its dungeons a lot over the years. One such victim to the wheels of time is the Scarlet Monastery. This dungeon (or these dungeons, I should say, each is their own separate instance) consists of the Armory, the Library, the Cathedral, and the Graveyard. 

In patch 5.0.4, these dungeons got rolled into two new revamped dungeons—the Halls and the confusingly-named Monastery. They were forever consigned to the annals of history (at least until World of Warcraft Classic came along). Well, it turns out you can get back to all four of these Classic dungeons right now.

All you have to do is queue up for the Hallow's End fight, the Headless Horseman, in the dungeon finder. Beating up this rhyming Scooby-Doo tier schmuck will let you snag a pumpkin with some goodies in it. One of these can be the Scarlet Key. 

Hoof it to the Monastery itself in Tirisfal Glades, and you'll be able to turn in the key, creating a clickable item that gives you a buff. The description reads «Retracing the steps of those who came before.» This gives you access to all four dungeons from the game's halcyon days. 

Now, granted, you could just hop on Classic if you want to experience them as they were—but there are transmog opportunities therein. As we all know, that's the real endgame of any MMO. It's also just nice to have multiple ways to access old content—whether rolling up a new character on a Classic server, or blitzing it on your retail main.

Honestly, one of my biggest problems with WoW's past attitude to expansions is just how much of the world gets scrapped or forgotten about. This game's been out for 19 whole years, but a mix of revamps and irrelevance leaves miles of it neglected. Letting players access areas like