Hmm... From what you say, am I correct in guessing that your game is an RPG of some sort? If not, what is it?

What are your goals?

One way or another, there should be a number of options, depending on what tools you're using (are you using OpenGL/DirecetX, some engine or another, text...?).

If you're using 2D, you could go the way of the Baldur's Gate series, and use enormous image backdrops combined with, if I'm not much mistaken, "active" regions (specified as polygons, I would imagine) which might act as doors, script triggers, encounter spawn points, traps, etc.

If you're using 3D, then why not simply place objects as you like, where you like?

Perhaps it would help if you were to elaborate a little on your game and tools...

You could break down your environments into "rooms" and use text to describe each room instead of graphics.

You could use a combination of graphics and text descriptors to describe each room that your character encounters.

You could do away with graphics and text altogether and represent everything in the current room in a list (An RPG Without Space).

You could represent your journeys simply on a map with icons, where each icon represents a room.

You could go "rogue" and utilize keyboard characters as a type of tile-based graphic to which go on a coordinate system (by the way, you will always need to have a coordinate system, to which is basically a grid with small spatial measurement units, to keep track of each actor's location).

You could go 2-D and use a side-scrolling perspective.

You could go 2-D and use a top-down perspective over a pre-rendered map (single picture), then place "hot spots" on this map.

You could piece together image "doodads" together of varied shapes and sizes on-the-fly whenever your character enters into a new area.

You could go 3-D.