http://top-10-list.org/2012/08/22/top-10-most-guarded-places-on-earth/2/
http://top-10-list.org/2010/05/30/top-10-restricted-places/2/
http://www.smh.com.au/travel/secret-spots-10-places-you-will-never-visit-20130311-2fvll.html
http://www.oddee.com/item_98792.aspx
http://listverse.com/2010/01/06/top-10-places-you-cant-go/
http://www.huffingtonpost.com/2013/12/29/places-you-cant-go_n_4442283.html