Plaza Ernesto Tornquist, Public square in Tornquist, Argentina.

Plaza Ernesto Tornquist is a public square in the town center featuring a central lake enclosed by walking paths and landscaped gardens. The Santa Rosa de Lima Church sits within the grounds as a notable structure on the site.

The plaza dates from 1895, when four blocks of 119 by 90 metres were laid out between today's Avenida E. Tornquist and Calle Italia. In 1905 the Tornquist family hired French landscape designer Carlos Thays, who merged the four blocks into one, placed the church at the centre facing the station and opened a curved carriage access to the atrium. In 1907 Thays sent plants by rail from Buenos Aires, including 110 white acacias and 110 silver poplars; many died in transit and the survivors were planted around the perimeter.

The plaza serves as the main gathering place where people from the town come together for events, celebrations, and daily leisure. The green spaces and pathways create a backdrop for community life throughout the year.

The four original blocks were merged into one park, so the square is crossed by Avenida E. Tornquist and Calle Italia. The lake's islands are linked by concrete footbridges from the 1990s, while the central bridge dates from Francisco Salamone's work. The church stands at the centre, facing the railway station.

The lake was not built for beauty: between 1921 and 1922, residents Wedelin Loffler and Ricardo Kugler proposed an artificial pond to cool the dynamo engines of the town's new power plant, completed in June 1922. Locals often assume it was ornamental. A Canadian totem on one of the islets, placed for Indigenous Peoples' Day, honours North American peoples rather than the Tehuelche or Pampas.