Chile and Peru share a land boundary of about that runs inland from the Pacific Ocean near Arica to the Andean Altiplano, together with a maritime boundary in the Pacific. The land boundary was fixed by the 1929 Treaty of Lima, which ended the dispute over Tacna and Arica that followed the War of the Pacific. The maritime boundary was set by the International Court of Justice in 2014.

The land boundary begins at the coast, and the two countries disagree about exactly where. Peru holds that it starts at a point called Concordia, as described in the 1929 treaty, while Chile holds that it starts at boundary marker No. 1 (Hito N.º 1), a short distance north. The two points lie on either side of a small coastal area known in Chile as the "land triangle".

The main crossing is between Tacna and Arica, where the two countries operate the integrated Chacalluta–Santa Rosa border complex. The land boundary meets the Bolivian border at a tripoint near the village of Visviri.

Course

Land boundary The land boundary is about long. Under Article 2 of the Treaty of Lima, it starts at a point on the coast called "Concordia", north of the bridge over the Lluta River. It then runs eastward, parallel to the Chilean section of the Arica–La Paz railway and from it. A bilateral Mixed Commission demarcated the line on the ground in 1929–1930, and the two governments define the starting point differently (see below).

Inland, the boundary climbs into the Andes and the Altiplano and ends at the Bolivia–Chile–Peru tripoint on the Ancomarca Plateau, near the village of Visviri.

Maritime boundary The maritime boundary starts where the parallel passing through Hito No. 1 meets the low-water line. It follows that parallel for 80 nautical miles, then turns southwest along a line equidistant from the two coasts until it reaches the 200-nautical-mile limit measured from Chile's baselines. The line is the one fixed by the ICJ in 2014.

History

Background

Historians disagree about the northern limit of colonial Chile at the time of independence. According to one view, there was no defined boundary between the Viceroyalty of Peru and the Captaincy General of Chile: Peru bordered Charcas to the south, as Chile did to the north. Other authors, mostly Chilean, argue that Chile and Peru met at the Loa River and that Bolivia occupied the Atacama corridor unlawfully, since in their view it belonged exclusively to Chile.

War of the Pacific and the Treaty of Ancón

The War of the Pacific began in 1879, and Chile defeated Peru and Bolivia and gained the northern regions it holds today. In the Treaty of Ancón of 1883, Peru ceded the province of Tarapacá to Chile permanently. The provinces of Tacna and Arica passed to Chilean control for ten years, after which a plebiscite was to decide their future. The plebiscite was never held, and the dispute over the two provinces dragged on for decades (see Tacna and Arica question and Chilenization of Tacna, Arica and Tarapacá).

Treaty of Lima

The question was settled by the Treaty of Lima, signed on 3 June 1929. Tacna returned to Peru and Arica remained with Chile, which set the present land boundary. The ICJ later described the treaty as the instrument that fixed the land boundary between the two states.

Starting point of the land boundary Although the Treaty of Lima fixed the land boundary, Chile and Peru later came to disagree about where it begins at the coast.

Peru holds that the boundary starts at the Concordia point defined in Article 2 of the treaty, on the seashore. It cites the treaty, its Complementary Protocol and the work of the 1929–1930 Mixed Commission. Chile holds that the boundary starts at Hito No. 1, the marker closest to the sea, and that the treaty placed the beginning of the land boundary there.

The ICJ did not decide the question. It noted that the treaty point and Hito No. 1 are different places, and it took the intersection of the parallel through Hito No. 1 with the low-water line as the start of the maritime boundary. After the 2014 judgment, Peru adopted a baseline law and a chart of its maritime limit, and President Ollanta Humala said these showed that the border begins at Concordia and "there is no other". Chile sent a diplomatic note of protest. The disagreement flared again in 2015, when Peru created the district of La Yarada–Los Palos, which borders Chile at Punto Concordia, south of Hito No. 1. Chile responded with a second diplomatic note.

Maritime delimitation

Peru instituted proceedings against Chile before the ICJ on 16 January 2008, asking the Court to delimit the maritime zones of the two states starting from Concordia. Chile maintained that an agreed maritime boundary already existed, while Peru argued that none existed. In its judgment of 27 January 2014, the Court found an agreed boundary along the parallel but only to a limited distance. It then drew an equidistance line to the 200-nautical-mile limit. Chile said it would abide by the ruling. The two states approved the coordinates of the boundary on 25 March 2014, in a record signed in Lima.

The ruling gave Peru about of sea that had been part of the zones Peru claimed. Before the ruling, two areas had a different legal status. The first, about , was administered by Chile as part of its exclusive economic zone. The second, , was regarded by Chile as high seas, open to all states.

Border crossings and communities The border runs through a desert region where Arica (Chile) and Tacna (Peru) are only about apart. A study of travelers at the Chacalluta crossing found that residents of the two cities cross the border so often that the area functions as a continuous cross-border territory despite the political line.

The main road crossing joins the Chilean complex at Chacalluta and the Peruvian complex at Santa Rosa. On 16 October 2017 the two governments inaugurated a juxtaposed control system there, in which exit checks for Chile are done at the Peruvian complex and entry checks at the Chilean one. About seven million people and one million vehicles were expected to cross each year, and Chile's customs director called Chacalluta the land crossing with the most passenger traffic in the country.

On the Chilean side the main border localities are Arica and Visviri, and on the Peruvian side Tacna and Tarata.

Migration

During the Venezuelan migration into Chile in the early 2020s, migrants seeking to enter Chile tended to avoid the Chile–Peru border because it was better guarded than the Bolivia–Chile border.

In late 2025 the flow reversed. After Chile tightened its migration policies, migrants, mostly Venezuelan, tried to leave Chile through Chacalluta to return home or travel on, but many lacked the documents Peru requires and were stranded between the two complexes. On 28 November 2025 Peru's interim president, José Jerí, declared a 60-day state of emergency in the Tacna districts of Palca, Tacna and La Yarada–Los Palos so that the armed forces could support the police at the border. More than 50 Venezuelan, Colombian, Ecuadorian and Haitian migrants, including children and older adults, were reported stranded on the road between the two complexes, and Peru's army reinforced surveillance of unauthorized crossing points. On 1 December 2025 a group of about 70 migrants forced its way through the Santa Rosa complex, and Peruvian police returned them to Chile.

See also Chilean–Peruvian territorial dispute Chilean–Peruvian maritime dispute Bolivia–Chile border Tarapacá migrant crisis

References