Black Temple is the most classic instance with lvl70 of 25 players, Which is located in the Shadowmoon Valley and includes 9 Bosses. The legendary Demo hunter Illidan Stormrage will accept player's challenge at the end. Illidan Stormrage is popular in Black Temple, in which has the legendary Weapon Warglaive of Azzinoth, cool style Tier 6 and gears. And with the upgrade of the patch, players can obtain many rare pets. 

Patch 7.2.5 is introducing a new mode of Timewalking - Raids! The first Timewalking Raid available will be the fan favorite Black Temple, open during Outland Timewalking. 
Black Temple Timewalking is a complete dungeon, in which players' level will be compressed to 70, and also item level to 141. The drops from the dungeon are same with before and all gears from Timewalking is ilvl 900 when looted by a level 110 player. The most worth expecting is DH. As long as you gained Warglaive of Azzinoth achievement, Subsequently running Black Temple in Timewalking Mode while having this achievement will award achievement I'll Hold These For You Until You Get Out and Arsenal: The Warglaives of Azzinoth, allowing Demon Hunters on your account to transmog their weapons to the original Warglaives.
The pets that drop in the regular Black Temple also drop in the Timewalking version of this raid. These are part of the Raiding with Leashes III: Drinkin' From the Sunwell achievement, which awards Holy Chime upon completion. also, you can buy that pet for AH by WoW Gold.
Maybe we will see more raid timewalking later to experience more classics!