The remains of one tower of the fort were found during digging for the MÃ tro ( rail mass-transit system ) in 1899 . These were moved to a park , the Square Henri-Galli , a few hundred meters away . Some undemolished remains of one tower of the fort were discovered during excavation for the MÃ tro ( rail mass-transit system ) in 1899 , and were moved to a park ( the Square Henri-Galli ) a few hundred metres away , where they are displayed today .