3D Interactive Tour Ideas

Hey All - I’m looking for some ideas on what software could be used with Flash to create a 3D environment of, for example a city block - where the user can use the arrow keys to ‘walk’ down the street and then turn the corner to view that street and it’s buildings.

Any ideas? I’ve looked at a variety of software options, but none so far really do what I need. I’m wondering if it would be more of a gaming engine that would provide the solution. Again, any help or ideas is appreciated! Thanks.