Spanish Army geolocates 19th‑century boundary markers along Andorra frontier

The Spanish Army has carried out a field review of the southern frontier with Andorra to geolocate and verify 19th‑century boundary markers using modern surveying equipment. The work, conducted in three consecutive campaigns beginning in 2023, involved teams from the Army Geographic Centre (Ceget) and the National Geographic Institute (IGN) and forms part of the technical phase of the Hispano‑Andorran Mixed Commission for Border Delimitation.

Technicians used the original placement of markers established between 1856 and 1863 as the legal and historical basis for the survey. That mid‑19th‑century delimitation was formalised in a notarial act signed by Andorran notary Rossend Jordana and his counterpart Salvador Galindo of La Seu d’Urgell, with participation from representatives of Sant Julià de Lòria, La Massana and several Catalan border villages. The work followed the line established in parallel with Spain–France arrangements deriving from the 1856 Treaty of Bayonne.

Survey teams located and documented the historic marks — often small crosses carved into rock — across frequently shaded, hard‑to‑access terrain. Many markers were partially obscured by moss or erosion. Using contemporary geodetic systems and modern instruments, teams recorded positions with better than five‑centimetre precision. Where conditions required, surveyors combined modern techniques with traditional field methods, including use of the vara castellana, an older Spanish unit of 83.59 centimetres employed in the original measurements.

Work covered much of the southern frontier, from the Setúria area through Montmelús to the Estany Engaït sector and nearby triple‑border zones, and was coordinated within the binational technical phase. Official conclusions from the field review have not yet been published.

The mixed commission was created after a dispute linked to the Planell de la Tosa photovoltaic project, which four years ago encroached some 50 square metres of Os de Civís and exposed the fragility of a delimitation that traces back to 1007 and was only partially formalised in later centuries. The recent fieldwork is presented by authorities as an effort to reconcile archival records and legal continuity with current geodetic techniques.

Andorra’s government spokesman Guillem Casal said the presence of Spanish military surveyors reflected routine data collection on Spanish territory and that Andorran teams are carrying out equivalent surveys on their side. Casal described the working atmosphere between delegations as very good and said the technical phase is expected to finish this year, with a further technical meeting planned in Madrid in spring 2026. After the technical work is completed, documentation will be passed to the mixed commission to resolve any points requiring political decisions.