Luján was established in 1755, when this was the very edge of the Spanish colonial world - flat, open country where the settled lands gave way to the territory of the Indigenous peoples of the pampas. The Río Luján gave the town its name and its reason to exist, a thread of water and a stopping place on the routes inland. The great neogothic basilica that now defines the skyline came much later, begun in 1889 and finished in the 1930s. Long before those towers rose, Luján was already a destination, drawing pilgrims to the modest shrine of the Virgin that had stood here since the 1600s. The grandeur arrived; the devotion was always the point.

What sets Luján apart is the sheer scale of belief it gathers. The basilica honors the Virgin of Luján, patron saint of Argentina, and houses her tiny statue beneath a copper roof, behind bronze doors, in a building that towers over the surrounding flatland. In its gallery stands a monumental organ built by the celebrated French firm of Cavaillé-Coll, an instrument that fell into disrepair but has drawn long efforts toward restoration. Around the church, the sacred and the everyday mingle without friction: stalls of religious keepsakes, the smoke of asado grills, families on a day out. Luján has learned to be a holy city and an ordinary one in the same breath, and somehow neither role crowds out the other.

A few steps from the basilica, the Enrique Udaondo museum complex holds the secular treasures of Luján - and they are remarkable. Housed in the colonial residence of the Viceroy and the old town hall, it displays La Porteña, Argentina's very first steam locomotive, and Plus Ultra, the first seaplane to fly from Europe to Argentina. Strangest of all are the preserved prison cells where two utterly opposed figures were once held: Colonel William Carr Beresford, commander of the British forces who invaded Buenos Aires in 1806, and General Cornelio Saavedra, who in 1810 led the first national government of an independent Argentina. A captured invader and a founding father, confined within the same walls - Luján keeps both, without choosing sides.

Not all of Luján's faith is loud. Since 1987, Benedictine monks of the Cono-Sur Congregation have lived quietly at the Abadía de San Benito on the city's outskirts, supporting themselves through agriculture and publishing and offering retreat to those who need silence rather than crowds. It is a fitting counterpoint to the great pilgrimages: where a million walkers fill the roads one Sunday each October, a handful of monks keep a steadier, quieter rhythm through all the other days of the year. Between the roaring devotion of the pilgrimage and the murmured prayers of the abbey, Luján holds the whole spectrum of belief. Add the captured British colonel and the founding general in their museum cells, the first locomotive and the first transatlantic seaplane parked nearby, and this pampas city by the Río Luján turns out to hold a remarkable amount of Argentina - sacred and secular alike - in one easily reached place.