The site sits directly over the original, failed first settlement of Buenos Aires founded by Pedro de Mendoza in 1536.
The property contains a complex network of 18th-century brick tunnels that were forgotten and filled with debris for over a hundred years.
It served as a 'conventillo' (tenement housing) for immigrant families in the late 19th century before its abandonment.
Archeologists discovered thousands of artifacts including pottery shards, coins, and everyday items dating back to the colonial period.
The mansion was built in 1860 using Italianate architecture style, masking the older, historic structures beneath its floors.
The underground stream, Tercero del Sur, still flows beneath the foundations, influencing the site's unique architectural preservation.
During the excavation, workers removed over 250 tons of earth and debris by hand to reveal the original cisterns.
El Zanjón de Granados is a restored urban archaeological complex that reveals a subterranean network of tunnels and cisterns beneath a 19th-century mansion. The site sits atop the original 1536 foundation site of Buenos Aires, located on the banks of the now-underground Tercero del Sur stream. Restoration efforts began in 1985 after owner Jorge Eckstein discovered the ruins while renovating a derelict property. Visitors traverse limestone walls, brick arches, and complex drainage systems dating back to the colonial era. The structure showcases the layered architectural history of the San Telmo district, transitioning from indigenous geography to a wealthy 1860s residence and eventually a conventillo. It is one of the most significant archaeological salvage projects in the city, providing a rare cross-section of Buenos Aires' geological and social development.
The dramatic, illuminated view of the subterranean brick tunnels from the lower walkway levels.
Book a guided tour in advance, as independent exploration of the tunnels is restricted.
Wear comfortable, flat walking shoes, as the subterranean paths feature uneven historic flooring.
Bring a light jacket as the underground temperature remains cool and damp regardless of the season.
Do not attempt to walk in without a reservation, as access is almost exclusively provided via scheduled guided tours.
Closed on Mondays; reservations are required for all guided tours.
Refrain from touching the fragile brickwork and historical artifacts; follow the guide's instructions regarding photography in restricted zones.
