The sewers.

The Sewers is a setting in the third party mod Eternal Damnation. Since the doors of the Museum were locked, the only way to leave the place was via the sewers. When John Murray arrives to the sewers, he is confronted at several stages by men using masks and lab robes. The sewers introduce a new type of zombies: the crawlers, which are regular zombies with burned skin and no clothes. At some point in the way through the sewers, a hippo breaks a wooden wall and attacks John. At the end of the sewers, John is confronted by a group of masked men and 2 hippos. After this final battle, John exits to Newlow.