While the area between Schwedter Straße and Schönhauser Allee served as a space for physical exercise among the military and residents, west of Schwedter Straße was Nordbahnhof (Northern Train Station). This was the terminus of the Northern Railway Berlin (Berlin-Stralsund); it extended to the corner of Schwedter Straße and Bernauer Straße.
On the grounds of today’s Mauerpark stood in the 19th and 20th centuries one of the most widely used terminus stations in Berlin. On a city map, you can still see how the railway from the north runs in a straight line toward Bornholmer Str. Station, then turns to the east and west along the Ringbahn.
The straight stretch of land that now occupies Mauerpark held the tracks of the former Nordbahnhof. The Prussian Northern Railway, which since 1878 connected Berlin with Stralsund, ended here. The first section, and with it a train station close to the center of Berlin, opened on July 10, 1877.
The station was located at Eberswalder Str., opposite the confluence of Schwedter and Oderberger Str., today the southern entrance to the park. The Gleim Tunnel, which connects the two bordering neighborhoods of Wedding and Prenzlauer Berg at the north end of the park, is still recognizable as a piece of the former train tracks. However, by the end of the 19th century, passenger traffic on the Northern Railway was moved to the larger and more centrally located station of Stettiner Bahnhof, which was renamed as “Nordbahnhoff” in 1950 for political reasons.
The old Northern Railway station was used for freight transport until after the Second World War, operating under the name Northern Railway Freight Yard or Eberswalder Str. Freight Yard.
More info: “Güterbahnhof Eberswalder Straße” at berlinergeschichte.de (German)