Pick up the crowbar of research scientist Gordon Freeman, who finds himself on an alien-infested Earth being picked to the bone, its resources depleted, its populace dwindling. Freeman is thrust into the unenviable role of rescuing the world from the wrong he unleashed back at Black Mesa. And a lot of people, people he cares about, are counting on him.
This 17 or so minute video will walk you through using displacement maps to make hills, like the ones in the HL2 coast levels.
Dystopia requires more than a simple info_player_start for a barebones map. I'll go into a bit of detail in this tutorial on what itis you need for...