Obelisco de La Plata, Granite obelisk monument in Plaza San Martin, La Plata, Argentina.

The Obelisco de La Plata is a red granite monument standing in Plaza San Martin, supported by a rectangular base. The structure narrows upward into a flattened pyramid shape and is composed of five separate stone sections.

The Obelisco de La Plata was built in 1932 and inaugurated on 19 November of that year for the fiftieth anniversary of the city's founding. It was an initiative of the Centro de Ingenieros de la Provincia de Buenos Aires, with a design by engineer José Negri, as a tribute to the technicians who laid out and built La Plata.

The monument carries inscriptions on its side facing 6th Street that document the role of engineers in the city's development. These carved words make visible the importance of the technical professionals who shaped La Plata.

The monument sits at the intersection of streets 6 and 50 with diagonal 80, easily accessible by several public transit routes. The central location makes it a convenient stop during a walk through the downtown area.

The obelisk rests on a 20 m³ concrete block, to which the first stone was tied with iron beams. The five granite blocks are joined by concrete anchors cast into the lifting points of the hoisting apparatus. In the small square beside it lies a relief plan of La Plata set horizontally in cement.