sentences:  Whether it is around the cathedral, during repairs to a Wren church or on some building sites, archaeological excavation in the City often finds evidence of the Fire and of the rebuilding, especially along the waterfront where the fire rubble was left in the streets and alleys to heighten the ground level against the Thames.This means that not only are some of the pre-Fire buildings saved for excavation, with walls up to five feet high, but the post-Fire improvements can be seen