Denver neighborhoods and architecture

[Casey Andersen]

In all fairness this is not a strictly real estate investment related post, but, here goes:

I'll be visiting Denver for a weekend (planning to rent a car), and I love all things real estate and architecture.  Any suggestions on neighborhoods or buildings not to miss?  Any ideas from locals?

Where are the up and coming areas, high end neighborhoods, best investment opportunities, modern residential neighborhiids?

Thanks!