The well, which, according to surviving engravings and several historical maps and plans, stood in the middle of the Fish Market, was probably established at the turn of the 14th and 15th centuries and probably served until 1820, when it was filled in. It had stone timbering with decoration and one or two levelling steps. It did not originally have a wrought-iron grille, which did not adorn it until the 17th century.

Marking the well on several plans helped to estimate quite accurately where it was probably originally located. In the summer of 1999, exploratory work began in the middle of the square. When the excavation of the exploratory shaft began, a fragment of the brick vault was found two metres below the pavement, which had been used to cover the well after it had been filled in. The vault was intended to prevent further subsidence of the soil under the pavement of the square and it fulfilled its task perfectly. Underneath, a preserved stone well with a diameter of 1.4 m was found, completely filled in with earth and ballast. The backfill was gradually removed down to the bottom level to a depth of 14.5 m. After cleaning, the well was re-paired and the missing stones were filled in.

An interesting discovery awaited at a depth of 11 m. At this level, an octagonal oak-wood well wreath is embedded in the lining, which means that the well was additionally deepened by 3.5 m, probably due to a drop in the water table. This is confirmed by the surface of the stones, which is much more smoothed above the wreath than below it.

The water column of the well has risen to a height of 3 m since the water pumping was stopped after the repairs were completed. The well is now temporarily covered and waiting to be reintegrated into the square as in the past.