There is an excellent, long-term exhibition of plaster casts from
the Metropolitan Museum collection on view at the Queens Museum
in New York.  These have been restored and nicely installed.
 
The Queens Museum is the same place with the huge, minutely
detailed relief map of New York, with every building accounted
for (and recently updated, too).  For people who "collect"
museums the way birdwatchers collect sightings, Queens is a
*must-see*.  [A rare bird?]
 
Charles Desmarais