worlds-second-tallest-building-opens-to-much-jubilation

http://curbed.com/archives/2012/05/23/worlds-second-tallest-building-opens-to-much-jubilation.php

Urban Underground facilities

http://en.wikipedia.org/wiki/Underground_city ,

https://en.wikipedia.org/wiki/Underground_city#Japan 

http://en.wikipedia.org/wiki/London_Underground ,
http://www.tfl.gov.uk/modalpages/2625.aspx , http://www.tfl.gov.uk/gettingaround/1106.aspx

https://en.wikipedia.org/wiki/Underground_city#North_America ,
http://en.wikipedia.org/wiki/Underground_City,_Montreal

https://en.wikipedia.org/wiki/Cities_of_the_Underworld , 

https://en.wikipedia.org/wiki/Utility_tunnel

https://jfdatalinks.blogspot.com/search?q=UTL , 
https://jfdatalinks.blogspot.com/search?q=UTDL