The settlement began the way half the towns of the Alto Paranaiba began: someone washed gravel in a stream and found something hard and bright in the pan. The creek was the Agua Suja, a tributary of the Bagagem River, and the first diamond came out of it in 1857, a few years before the Paraguayan War began. This was diamond country in a serious way - the same Bagagem drainage, a short distance north, produced the Star of the South, one of the largest diamonds ever found in Brazil. Prospectors here worked the gravels with pans and sluices in water that ran opaque with the sediment they stirred up, and that water gave the camp its unlovely name. The garimpeiros are long gone. The name lasted longer than they did.

Along with the picks and the pans came a chapel, raised in honor of Nossa Senhora da Abadia, Our Lady of Abadia, with an image brought over from Portugal. The chapel of Nossa Senhora d'Abadia de Agua Suja anchored the growing settlement, and devotion to the image outlived the diamonds by a century and counting. By 1926 something on the order of fifty thousand romeiros were arriving each year to pray before the statue, a staggering number for an interior mining village with no railroad, and the community began building a sanctuary large enough to hold them. That building is now the Santuario Basilica Nossa Senhora da Abadia de Agua Suja, and it is the reason anyone in Minas Gerais knows the town's name.

The festival runs from August 6 to August 15, and the archdiocese of Uberaba counts it as the largest religious celebration in the Triangulo Mineiro. Pilgrims come on foot, on horseback, by bicycle, in cars and buses and ox carts, from across Minas Gerais and from other states, some walking for days on the roads that converge here. The crowds run into the hundreds of thousands, concentrated on the closing day. Behind the scale is a lot of individual arithmetic that visitors rarely see: a promise made during an illness, a vow to walk the last stretch barefoot, a photograph carried in a pocket for someone who could not come. The town accommodates all of it, then empties out, then does it again the following August.

Romaria became a municipality in its own right in 1962, and by then the new name had long since displaced Agua Suja in ordinary speech. It is a small jurisdiction, 402 square kilometers, with the town center sitting at 960 meters on the Alto Paranaiba plateau just north of BR-365, the federal highway that runs from the Goias state line east toward Montes Claros. Monte Carmelo is twenty kilometers away, Uberlandia and Patrocinio each about seventy-five, Belo Horizonte a distant 511. Estrela do Sul and Monte Carmelo border it on the north, Araguari to the west, Nova Ponte and Indianopolis to the south.

Between festivals, Romaria is farm country and nothing else. The red soil of the cerrado, corrected with lime and irrigated, grows some of the best coffee in Brazil; the municipality had 5,200 hectares of it in 2006, alongside 9,500 hectares of soybeans and 6,500 of corn, plus cotton, beans, passion fruit, and rice. Cattle are raised for beef and dairy, 7,700 head across 175 rural establishments. Around 2,000 people depend directly on agriculture, in a municipality of 3,520 - which is to say nearly everyone. In 2007 there were 391 automobiles in the entire municipality, roughly one for every eight inhabitants, and not a single bank branch. For ten days a year, none of that is what the town is about.