La Fonda right on the old Santa Fe plaza. The hotel is historic having being built in the '20s, but compared to the native pueblos in the area, it is a modern youngster. Those pueblos are several thousand years old!
Having said that La Fonda has been updated, restored and thoughtfully modernized and is indeed a first class operation even though it looks like it could have been standing for much longer than it has. It is filled with amazing original and authentic art.
An example of how much effort has been made to keep it looking authentic... here is a photo of part of the hotel, but the structure in the foreground is actually a parking garage.