A dungeon at last! Apparently, lucky Paladins could obtain the portrait through other methods. As for Lu Li, it appeared that he didn't have such luck.
Stratholme was probably level 50, based off the level of the boss.
Despite this, the levels of the monsters didn't average out to be level 50 – they were around level 47 to level 48. Stratholme was also a dungeon well-known for its difficulty and was nothing like Zul'Farrak.
It was located on the Northwest side of Eastern Plagueland, and there were two entrances. The first entrance, known as the front door, was located in the blood zone. On the Eastern walls in the Undead zone was the other entrance, known as the back door. Those with the city keys, or a Thief with the Unlock skill would be able to open them.
For Lu Li, it was more convenient for him to take the back door. His Unlock was fully capable of opening it as well.