Creating interiors for games in Unity

Which software are you using for creating interiors (rooms, caves, hallways, etc.) for your games? Is there a simple program only for creating interiors? Or I must learn e.g. Blender? Do you know any good tutorials about interiors for games?

Well a software just for interiors, I have not heard a bout it, but yes you ca use blender or Cinema 4d both are great, Cinema 4d is an incredible tool for 3d graphics but it is incredible for interiors to so Good luck finding your choice Slavq.

Here some tuts on interiors: