You can reach Platz der Einheit square by tram from the Potsdam Main Rail Station.
The Platz der Einheit (Unity Square) is one of the places in town which emerged in the 18th century because the swampy terrain was not arable, and thus couldn't be used for the town extensions in any other way. Among these places, is what is known as the Plantage (the Plantation), which Lenné designed in 1850, with a tiny remnant still surviving in Yorckstraße and Bassinplatz square.
Platz der Einheit
At one time, the site of a large body of water whose name, the Faule See (Rotten Lake), must have referred to a foul smell. In the course of the First Town Extension, this lake was filled in 1722-1724, and bit by bit was surrounded by townhouses. Again and again during the following years, the marshy land was a recurring problem. Between 1786 and 1789, the area was built up, and under Frederick William II underwent its first conversion into a park. From this time until 1945, it bore the name Wilhelmplatz, became a popular strolling place for Potsdamers. In 1831, the terrain had to be solidified again and Lenné re-designed it. In 1845 an equestrian statue of Frederick William III marked the center of the square. Lenné re-designed the square again in 1862: depictions show two rows of trees bordering the square and diagonal pathways crossing it. In 1929 and 1979, sinking areas of the ground had to be evened out again. The last re-design of the square, oriented to Lenné's specifications, was carried out in preparation for the National Horticulture Show 2001.
The buildings surrounding the square were destroyed during World War II. The only building left standing was the post office, but it was also severely damaged. Following a number of predecessor buildings, the first of which was built alongside the canal already in 1783-84, a new post office building was built here after 1894, and Emperor William II himself officially opened it on March 10, 1900. In 1936, the neo-Baroque building lost the cupolas which had originally adorned the main entrance and the side towers.
Severely damaged in 1945, the building was rebuilt as the Potsdam Main Post Office.
To the left of the post office building, a commemorative plaque refers to the Potsdam synagogue which once stood here. Two synagogues had previously existed in Potsdam, the first dating back to 1748, and one was built at what was then Wilhelmplatz Square in 1767. A second was consecrated at this site in 1802. In 1898, Emperor William was presented with two drafts for a new building. He approved the design for a southern German neo-Baroque structure. The new building was consecrated in 1903, but was fated, as with many other such buildings in Germany, to be destroyed on November 9, 1938. It was then conserved to a lecture hall for the German Reichspost - Imperial Post Office - and fell victim to the 1945 air raid.
Opposite the main post office, located at the edge of the lawn, is the memorial for the victims of fascism, which was inaugurated on May 9, 1975.
At the intersection of Straße Am Kanal and Friedrich-Ebert-Straße stands the Memorial for the Unknown Deserter, designed by the Turkish sculptor Mehmet Aksoy (born 1939). The attempt to place the artwork in Bonn in 1989, the city for which it was created and paid for with donations, failed because of the considerable resistance of conservative groups. In August 1990, the city council decided to set up the memorial here in Potsdam, Bonn's sister city. After various provisional arrangements, the memorial was permanently included in the new design of the Platz der Einheit Square in 1999.