This site is well constructed, easy to navigate, and has a good site map. The online virtual tours for Van Gogh, Calder, and Cambodia earn a ranking of 5 on their own. They are offered in two different formats--virtual reality and no special requirements which allows all to see the exhibits. The entire site has much to offer those that appreciate art and those that are learning about art and how to view it. My student teachers and the public school teachers with whom I work are impressed with what is here. You will return to this site.
For the virtual tours at this site, you need a frames-enabled browser; 16" monitor (800 x 600 resolution) or larger; resized window to maximum width at 800 x 600 resolution; bandwidth considerations: file sizes vary from approximately 2k to 150k; allocate as much memory to your browser as possible. Also, virtual tours can be viewed with version 3.x of QuickTime or higher on any browser version 3.x or higher. Audio portions of the virtual tour are available in RealAudio (RealPlayer) or wav formats. The opening page of the tour has direct links to any plug-ins or downloads you might need.