Hadrian's Villa & urban-retreat concept

http://scholar.lib.vt.edu/theses/available/etd-05062005-093850/unrestricted/thesisbook.pdf

http://repository.up.ac.za/bitstream/handle/2263/29631/00front.pdf?sequence=1&isAllowed=y

http://idialab.org/virtual-hadrians-villa/

http://vwhl.clas.virginia.edu/villa/