Montfichet's Tower was a Norman fortress on Ludgate Hill, in the historic centre and central business district of which city? 
Montfichet's Tower: Montfichet's Tower (also known as Montfichet's Castle and/or spelt Mountfitchet's or Mountfiquit's) was a Norman fortress on Ludgate Hill in London, between where St Paul's Cathedral and City Thameslink railway station now stand.
i don't know