Asunción began as a river outpost established on 15 August 1537 by Juan de Salazar y Espinosa and other Spanish expeditionaries searching for routes into the continent. Built on a sheltered bay of the Paraguay River, it became a durable base after the failure of the first Buenos Aires settlement. Expeditions leaving Asunción founded or reinforced towns across the Río de la Plata basin, earning it the later title Mother of Cities. Guaraní alliances, coercion, kinship, mission activity, and labor were fundamental to this colonial expansion, though older narratives often centered only Spanish founders.

The city's early form grew irregularly along paths, ravines, river landings, orchards, and domestic compounds. It did not initially follow the rigid grid imposed in many Spanish American foundations. Casa Viola, the oldest surviving house in the group now called the Manzana de la Rivera, dates from the mid-eighteenth century and preserves a roofline set to an earlier street direction. Its adobe and timber construction, tiled roof, deep eaves, and rooms around a courtyard reflect local responses to heat, rain, and available materials. Later houses gradually aligned with a more regular urban plan.

Paraguay declared independence in 1811, and Asunción became the capital of a strongly centralized republic. Nineteenth-century governments erected institutions and residences that announced state power, including the nearby López Palace. The Paraguayan War of 1864 to 1870 devastated the country; allied troops occupied Asunción, residents were displaced, and buildings were damaged, looted, or repurposed. Reconstruction brought new immigrants, commercial styles, and imported materials. Within the Manzana, Casa Castelví, Casa Serra, and the early twentieth-century Casa Ballario record successive neoclassical, Italianate, and eclectic tastes beside older colonial fabric.

The block's survival became a public issue after the fall of Alfredo Stroessner's long dictatorship in 1989. Plans to clear the houses opposite the government palace for a monumental open space treated aging domestic buildings as obstacles to modernization. Architecture students and preservation advocates responded with the campaign Salvemos la Manzana frente al Palacio, arguing that ordinary houses held a history the capital could not replace. Municipal acquisition and restoration began in 1991. The campaign linked democratic reopening with the right to recover streets, buildings, and memories that authoritarian planning had marginalized.

The restored complex became the Centro Cultural de la Ciudad, bringing together nine historic houses and newer facilities under the popular name Manzana de la Rivera. Artist and cultural organizer Carlos Colombino served as its first director. Libraries, exhibition rooms, archives, workshops, gardens, cafés, and performance spaces gave the block an active civic role rather than preserving it as an empty period display. Later additions, including a municipal theater space, expanded programming. Each house retains a separate identity, allowing visitors to read changes in construction, taste, household organization, and street alignment across more than two centuries.

Today the Manzana faces both the Paraguay River and the ceremonial architecture of national government, a position that makes its modest scale especially meaningful. It represents colonial life, independence, war, immigration, dictatorship, and democratic preservation without reducing Asunción to a single founding moment. Conservation challenges include humidity, maintenance, redevelopment pressure, and the need to interpret Indigenous and working-class experiences alongside elite domestic history. The block endures because residents defended it, showing that historic urban identity can be renewed through cultural use and public argument rather than through demolition or nostalgic reconstruction.