This study presents the first comprehensive reconstruction of the 'New Jerusalem' Scroll from the Dead Sea, through integration of all the known fragments into a single entity. Secret ceremonies in the temple are discussed; an architectural reconstruction of the elements described in the scroll is presented, accompanied by computerized plans; a consideration of the tradition of planning the ideal city leads to an examination of the use of metrology, mathematics; and a number mysticism in the plan of the 'New Jerusalem'. A comparison is also made with the traditions of building orthogonal cities in Egypt, Greece, Rome and the Holy Land, as manifested in archaeological findings.