Innsbruck is another world that could be easily expanded with some great roads going out past the airport. Currently the world is very limited - but with a little work it could be so much better.
One of my IRL rides:
Haute Route Dolomites Stage 1 is the above route, the actual stage above was different to the planned one due to snow falls.
Also:
Tivoli at the bottom is where the tilted hotel is in Zwift (as in real life).
Headed down towards Brenner. That was quite a nice ride, not massively hilly - just nice.
Also nearby is Kühtai, another quite famous climb. Timmelsjoch is also not too far away.
If you wanted to make it a really huge world, it could be even made into a Dolomites world:
That would be incredible.