Archivo General de Indias

Standing between the Cathedral and the Alcázar, the Archivo General de Indias is the third building of Seville's UNESCO World Heritage Site, and the one most visitors walk straight past. That is a mistake, because it is free, rarely crowded and genuinely fascinating. The building was designed in the late sixteenth century, after plans by Juan de Herrera, the architect of El Escorial, as the Casa Lonja de Mercaderes, a merchants' exchange where traders could do business without using the Cathedral steps, which they had been doing to the clergy's annoyance. It is a sober, beautifully proportioned Renaissance block of brick and stone around a central courtyard. In 1785, King Charles III decided to gather all the documents relating to Spain's American and Asian territories, then scattered across Simancas, Madrid, Cádiz and Seville, in one place, and chose this building. The result is one of the most important archives in the world: more than forty-three thousand bundles of documents, around eighty million pages, and about eight thousand maps and plans, covering three centuries of empire, from the voyages of discovery to the independence of the American republics. Researchers still come from around the world to study them. Visitors see the grand upper floor, where a marble staircase leads to long vaulted galleries lined with tall shelves of Cuban mahogany and cedar, holding archive boxes, under coffered ceilings and stained-glass windows. Display cases hold original documents and facsimiles, which may include letters and papers signed by Columbus, Magellan, Hernán Cortés and Francisco Pizarro, and temporary exhibitions explore particular themes, from cartography to the lives of ordinary emigrants. Admission to both the permanent and temporary exhibitions is free.

Visiting: according to Seville's tourism board, the archive opens Tuesday to Saturday from morning to late afternoon, and on Sunday and holiday mornings, with last entry thirty minutes before closing; it is closed on Mondays. Check the official Ministry of Culture page before you go, as hours can change. There is a short security check at the entrance. A visit takes thirty to forty-five minutes, and the cool, hushed galleries are a welcome refuge from the heat and crowds of the Plaza del Triunfo. Guided tours in English are offered by private operators if you want more context.

Why it matters: the archive holds the paper trail of an empire — ships' manifests, royal decrees, maps of new territories, lawsuits, letters home from emigrants, and records of the conquests and their devastating consequences for the peoples of the Americas. The displays are selective, but even a short visit gives a sense of the scale of the Spanish enterprise and of Seville's central place in it, as the only port licensed to trade with the New World for much of the sixteenth and seventeenth centuries. That monopoly is why the Cathedral is so vast and the city so rich in palaces and churches.

Fitting it in: because it is free, quick and next to the two great monuments, the Archivo is easy to slot between them — after the Alcázar and before the Cathedral, for instance, or while you wait for a timed entry. Combine it with the Cathedral, the Alcázar and the Plaza del Triunfo for a complete UNESCO morning, then walk down the Avenida de la Constitución to the Torre del Oro and the river, following the route the treasure fleets' cargoes once took in reverse. Families with older children will find the explorers' signatures and old maps a good way into the story of the age of discovery, and the building's courtyard and staircase are a lesson in calm Renaissance proportion after the exuberance of the Alcázar next door.