Other
History of Mannerism Architecture
This site lists a few different famous examples of Mannerist architecture from the 16th and 17th centuries. Click on the link and receive a large image and a biography of the work. Brief, but good information.
Curated OER
Blufton College: Images of Palazzo Chiericati
This site from the Blufton College is a collection of photographs of La Rotonda and explanations next to each one. Links are also available at the bottom of the page for other architectural wonders.