Here is a list of geodesic domes that are accessible or open to the public, and worth checking out.
USA
The Biophere 2 near Tucson, Arizona has two large geodesic domes. More photos of Biosphere 2
CANADA
http://kathyschrock.net/domehome/domehome.htm http://www.inetarena.com/~candlish/geo--dome.html http://www.insite.com.br/rodrigo/bucky/geodome.html http://www.yesmag.bc.ca/projects/geodesic.html http://niagara.rivier.edu/students/mneville/geodesic/dome.htm http://www.together.net/~thorton/dome/