The swamp is south of Lumbridge city. In it, there are 2 houses with NPCs, many trees, pools, and the lumbridge mines. It serves as a gateway between Lumbridge, Draynor, a dirt path, an abandoned campsite, and the Wizards Tower.
There are many scary and high level monsters here. They include banshees (Lvl. 23), the forgotten (Lvl. 26, look like giant goblins/zombies), and the returned (Lvl. 27, look like wither skeletons). Also, this is home to skeletons (Lvl 26.), and the overpowered jelly (Lvl. 78). I advise that you DO NOT hit these, unless you are over level 50, and over level 80 for jellies for grinding.