Plaza de armas de Chillán, Central plaza and park in Chillán, Chile.

The Plaza de Armas is Chillán's central square, featuring large open spaces and mature trees that provide shade and define the area's character. The plaza is bordered by four streets and remains free to visit year-round.

The square marks the exact site of Chillán's fourth and final founding, after the 1835 Concepción earthquake destroyed the city then located at Alto de la Horca in Chillán Viejo. Carlos Lozier drew a checkerboard plan centred on this square and laid out four equidistant plazas around it. In 1910 Roberto Negri sculpted the O'Higgins statue, unveiled only in 1919 after locals improvised the ceremony.

The central monument is Roberto Negri's statue of Bernardo O'Higgins, made in 1910 for Chile's Centennial but unveiled only in 1919 after locals, gathered at the Municipal Theatre, demanded an improvised ceremony. It depicts O'Higgins's 1823 abdication, with scenes of the battles of Rancagua and El Roble below and Clio holding a laurel wreath. Nearby stands a replica of "Europa" from Virginio Arias's Continents series.

The plaza sits at the exact centre of the Las Cuatro Avenidas sector, with the Edificio de los Servicios Públicos to the north, the Catedral de Chillán to the east and the municipal buildings, including the Teatro Municipal, to the west. The Paseo peatonal Arauco and the Edificio de Los dos Cuyanos lie to the south-east. A 2022 remodelling proposal, approved by the municipality but never presented to the regional government, foresaw semi-underground public toilets.

The O'Higgins statue was finished by Argentine sculptor Roberto Negri for the 1910 Centennial, but Santiago authorities never arranged a formal unveiling. After an event at the Municipal Theater, locals demanded it be revealed and staged an improvised ceremony in 1919. Its base shows the battles of Rancagua and El Roble and Clio with a laurel crown.