We haven't gotten to the Badlands yet, but since we can enter Uldaman, its only instance from about Level 35, and the 40's are going to be very busy, I didn't want to neglect it. The Badlands are located due south of Loch Modan, and the entrance to Uldaman is located in an excavation site on the northern border. The evil Dark Iron dwarves have unearthed the entrance to a long-buried city created by the Titans, massive beings that used to rule the planet, and as you explore, you learn a lot about the history of Azeroth, and dwarves in particular.
Legend has it that the Titans are a race of massive, metallic creatures that travel the universe and bring life to planets. Uldaman is one of three known cities in Azeroth that housed the Titans, and as the Dark Irons dig, they unearth this massive vault, and unfortunately, its numerous traps and troggs, which we come to learn were the Titans' first, and failed, attempt to create life on Azeroth.
A short way into Uldaman, we come upon the game's first reference to the Indiana Jones series. The game has become known for its many pop culture references and in-jokes, but by far, the most referenced character is Indy. In this instance, you might assemble a staff with a headpiece and hold it at a specific place so that it shines on a miniature city map in order to progress. However, in this case, the process doesn't reveal the location of the Well of Souls...it releases a giant Titan woman who is PISSED.
After defeating her, you progress further into the earth, and come upon more elaborate traps and safeguards. The final boss is Archaedas, a massive stone giant constructed by the Titans to protect the final vault. Inside the vault, you are able to access a recorded message of a Titan Lore Keeper, who informs you that the Dwarves are descendants of creatures created by the Titans themselves, in an effort to make something that was the mortal embodiment of earth's resilience.