Interdimensional Traveler

You walk in the 7-11 and get a slushie. You ask the clerk what the deal is with the other side of the river. He tells you that the city on the other side of the river was abandoned because people just got bored with it. The only people who still live there are criminals hiding from the law, zombies, werewolves, zombie and werewolf hunters who venture into the old side of town, and a handful of people who refuse to leave their homes on the other side, despite being alone without any city services enjoyed on this side of the river (and having to put up with zombies and werewolves). He also says that piranhas were placed in the river to discourage people from going back to the old city, with its dangers. Now you're glad you didn't try to swim across the river.