It’s hard to imagine a D&D adventure that doesn’t involve travel. Most PCs have a back-story that involves them leaving home in order to see the word and seek adventures. Who wants to stay in one location when there’s a whole world of excitement out there? If you do it right, there could be plenty of characters who are very content and even excited to stay in one place.
Location, Location, Location
In order for a campaign set in one location to really work the setting has to be interesting. I’ve participated in two campaigns that were set in one location. Once the setting was a lavish Tavern/Inn called the Sun & Moon, the other was set on board a pirate ship. In both cases the locations were as much a character as the other NPCs.
The Sun & Moon Tavern was a large structure that was more than just a taproom and a few rooms for rent. It also included a small theater, a courtyard garden, and even a Wizard’s tower. The setting varied enough that the PCs never got bored hanging around.
The adventure on the ship brought its own excitement. The ship itself was interesting, but the fact that it was a vehicle meant that we could stop at various ports whenever the plot called for it. But even so, the majority of the adventuring took place on the ship, at sea, and usually involved ship-to-ship battles or combat against giant solo monsters.
Just think of your favourite sit-com, and chances are it takes place in only one location. Most take place entirely on one or two sets and these are usually part of the same building. The fact that most of the action involving the principle cast happens in one place rarely hurts the show. Some of the most popular and longest running shows took place in only one or two locations (e.g., All In The Family, Cheers, Gilligan’s Island, Two and a Half Men, and Night Court).