Try Northwatch keep, all the way at the top left of the map, the keep is guarded by thalmor, so there is plenty of high elf blood to harvest. --- "the only noobs are the noobs who accuse others of being noobs"-Asterisk_Ninja
Or if you've done the main quest, go to the Thalmor Embassy (gate should be locked) and Fus Roh Dah someone inside. They will come running out and attack you so kill one, harvest it, then GTFO!!!!! --- "Sony should make a Blu-Ray less PS3"-videogamer1030
Can't you simply loot an already-dead high elf corpse for the blood? If so, you should find a Thalmor corpse near the Shrine to Talos in the vicinity of Falkreath. It's the earliest possible instance of looting a Thalmor robe, too, as well as some neat leveled loot. I got Thalmor robes, a silver sword (!) and an enchanted helm.
There's also a bunch of worshippers of Taos strewn about there, dead. There was a huge fight there. More loot, lol. --- ** PSN ID: GenocideHeart ** Does Hydlide really count as a game? I thought it was supposed to be some kind of torture session. --Tocawe