Manzana de las Luces and Subterranean Jesuit Tunnels

Why is it significant?

You are now standing at the threshold of the Manzana de las Luces, or the Block of the Illuminations, bordered by the streets Bolívar, Moreno, Alsina, and Perú.

Key Facts

Open the walk

You are now standing at the threshold of the Manzana de las Luces, or the Block of the Illuminations, bordered by the streets Bolívar, Moreno, Alsina, and Perú. In 1661, the Society of Jesus established their primary college and monastic compound on this plot, transforming it into the intellectual and scientific center of the colonial Río de la Plata. Following the expulsion of the Jesuits by the Spanish Crown in 1767, this city block became the intellectual incubator of independent Argentina: housing the Royal College of San Carlos, the National Library founded by Mariano Moreno in 1810, the University of Buenos Aires established in 1821, and the early national congress sessions.

In 1821, Argentine newspaper editor Vicente López y Planes coined the poetic name Manzana de las Luces in honor of the exceptional concentration of Enlightenment knowledge and university faculties flourishing inside these historic cloisters.

Yet beneath these serene colonial lecture halls and heavy masonry courtyards lies an enigmatic labyrinth. In the late seventeenth and early eighteenth centuries, the Jesuits excavated an intricate network of arched subterranean tunnels dug directly into the dense pampean clay. Connected without mortar, these underground galleries linked the Jesuit compound to the colonial fort at the waterfront, the church of San Ignacio, and several southern convents. Archaeological rediscoveries in 1912 revealed that the tunnels served multiple clandestine functions: as defensive escape routes during pirate or Portuguese raids, secret ammunition stores, and conduits for unmonitored trade. In the adjoining Church of San Ignacio, consecrated in 1722, you can admire the oldest standing church interior in Buenos Aires.

Walking through these ancient brick vaulted corridors feels like peeling back four centuries of cloistered scholarship and whispered political intrigue.

Head north on Calle Perú for one block to reach the grand clock tower of the Palacio de la Legislatura.