Here, on Patan's Durbar Square, stands the valley's greatest concentration of major temples and historic buildings.
Here, on Patan's Durbar Square there is a large amount of temples in a spmall area. 
mnli hypothesis: Here, on Patan's Durbar Square there is a large amount of temples in a spmall area.  premise: Here, on Patan's Durbar Square, stands the valley's greatest concentration of major temples and historic buildings.