My wife and I are in DC for a week of vacation, etc.. We come here a lot and have done all the major museums many times over. We did some again but I made a point to see some of the others.
The National Building Museum, housing in the former Federal Pension Building, is very nice.
First, Its a really fantastic building.
Second, its a fascinating museum, too.
I'd recommend anyone who can should see this - its free, too (you tax dollars at work).
http://www.nbm.org/about-us/ab...storic-building.html
On the second floor are a bunch of exhibits on the history of how we've laid out or streets and cities, and on building techniques and architectural styles, etc. Full size examples of how things were built all the way back to when its was just mud huts to today, as well as beautiful models - most are around HO scale - of the progress in architecture, etc., models famous or example buildings (Mt. Vernon, Falling Water, Cape Cod mansions, Santa Fe Governor's Palace, typical Levit-Town type house, etc. I picked up a few tricks studying them and learned quite a few little "clues" to arranging realism of the 1950s (the time period I model on my layout) by studying the exhibits - they have a lot of ten-minute long videos you can press to play. Had a wonderful afternoon of it and learned a lot.