Mysterious room and centuries-old wooden pipes discovered beneath Poznań Old Market Square

Archeological works are being carried out in Poznań Old Town, due to ongoing renovation of the Old Market Square surface. Experts are examining spaces that will be used for new rainwater tanks and wastewater separators, underground toilets and waste containers, as well as electrical substation.

The renovation crew have recently came across a concrete structure located on the western part of Old Market Square, between the Guardhouse (Odwach) and Municipal Gallery Arsenal (Galeria Miejska Arsenał).

Initially it was believed the structure was a water tank, as it was half-filled with water.

The water had been pumped out under the supervision of archeologists, who later put a camera inside and precisely measured the room - it is approx. 5 metres high, 14 metres long and 8 metres wide. The researchers also found fragments of cut cables, which led them to the conclusion that two large electricity transformers, used for powering trams, had once been located there.

"According to municipal office reports, construction of such a room was financed by the city power plant and completed in 1931. This infrastructure is a remnant of a tram route that once led to Old Market Square. It was the first tram route in Poznań, it ran from the railway station - initially horse-drawn, and later electric," Poznań City Hall informed.

The first trams - at the time horse-drawn - arrived at Old Market Square on July 31, 1880. Eighteen years later, electric trams started to operate on this route. They would enter the market going down the then Nowa Street (today's Paderewskiego Street). The road was steep and very dangerous as pacing trams had to make a sharp turn left. In 1912, a tragic accident took place - a derailed tram smashed into a clothes store, killing two people.

Trams would take passengers to Old Market Square until March 17, 1955. The route was cancelled in order to protect Old Town heritage sites, which had been negatively affected by tram-induced ground vibrations.

Now, the discovered former transformer room will most likely be made watertight and later covered beneath the ground again.

Another interesting trace of history found at Old Market Square are wooden water pipes, most likely dating back to the 17th century. The way they had been made suggests their age - at the time water mains were being drilled inside broad tree trunks. They have survived up to this day because they were placed on a lightly damp ground. A secured sample of the old pipeline is now going to be examined by dendrochronology experts, who will try to assess its age more precisely.

Poznań City Hall informed that, as part of the renovation of Old Market Square, the underground infrastructure would be replaced and rainwater tanks would be built. A new and even surface will appear at the square and streets leading to it. Some historic materials will be used for that purpose: cobblestones, kerbstones and granite pavement slabs. The market will also have green spaces in the form of flower beds with trees and benches.

Due to the renovation of the Old Market Square, many detours and traffic changes have been introduced. There is much less space for pedestrians, for instance, it is very difficult to watch the famous Poznań Goats' head-butting display. To address the issue, a decision has been made the attraction will be displayed more often.

Restaurant and bar gardens had to be closed for the duration of the works, but some of them have reopened at Freedom Square.

The renovation of Poznań Old Market Square is to be completed by the end 2023.