A Frizz Restaurant web page has an interesting discussion of the French Colonial architecture in Phnom Penh. It talks about the famous rococo palace "fixer-upper" that I used in my introduction. The building is in a decayed state, but evidently it has been purchased by the FCC Hotel Group. Restoration was supposed to have started in mid-2008, but nothing had happened by March 2009, when I was there (probably because of the bad global economy). The plan is to make it a luxury hotel with a French bistro downstairs and a connection to the FCC complex just behind it. The exact history of the house is unknown, but it was probably built in the 1920s. It's a typical French colonial building, but incorporates a whole combination of styles, including impressive Corinthian capitals and intricate sculptural designs.
The old part of the city along Sisowath Quay and along Norodom Boulevard was built during French colonial times and many of the old buildings still remain. Some have been restored (like the UNESCO building next to the old rococo palace) but quite a few are neglected and some may be beyond repair.