I.6.1 Parapet

A parapet in a rampart.  For the purposes of Lotus Green DC fortified data center facilities, a parapet is a single fortified tower (small castle) that is mostly or fully underground, and is integrated with a rampart.

rampart: an earthen embankment that surrounds the parapet and functions as a defensive wall and insulator.

references

defensive wall http://en.wikipedia.org/wiki/Defensive_wall 

parapet http://en.wikipedia.org/wiki/Parapet  

rampart "A type of defensive wall consisting of a low earthen embankment topped by a parapet or palisade"  http://en.wikipedia.org/wiki/Rampart