The Last Rites quest in Wrath Classic can be a bit tricky to get to. The quest text isn't clear and the location itself is pretty misleading, meaning you can easily find yourself in the wrong place with nothing to help you figure out where you're supposed to go.
Even if you did the quest years ago when the original Wrath of the Lich King expansion launched, you may have forgotten the details. This can be frustrating if you want to get to level 80 as quickly as possible, so this guide should help point you in the right direction. Here's how to complete the Last Rites quest in Wrath Classic, including where to go to meet Thassarian.
WotLK Last Rites quest: Where to meet Thassarian
Last Rites is a quest found in Borean Tundra and you pick it up from Thassarian at Death's Strand, southeast of Taunka'le Village. The quest tells you to go to the Temple City of En'kilah, to the north, and use the teleportation orb to reach Naxxanar and meet Thassarian there. This may sound simple enough but it's easy to get lost.
The first part is fairly straightforward. Head through the gates of En'kilah and you should see a glowing white pillar of light on a platform to your right. Step into the light and you'll be teleported to Naxxanar.
There should be a set of steps ahead of you, and two enemies guarding a walkway at the top. Kill these two enemies to get them out of the way but instead of continuing forward, turn around so you're facing the way you came. Follow the circular pathway around to either side and you'll find a short ramp that takes you to another glowing white teleporter, directly above the one you entered through.
Once you're through here, you'll find Thassarian directly in front of you. Speak to him to initiate the next stage where you'll help him defeat Prince Valanar. Just be aware that this can be a pretty tough fight so you might want to bring a couple of friends to help you out.