Why Isla de Flores stands out
Isla de Flores is best known for its 19th-century lighthouse, the so-called 'most expensive lighthouse in the world,' which was the subject of the 1819 Treaty of the Farola and cost the Banda Oriental the Misiones Orientales. It is also strongly associated with its role as a maritime lazaretto, where arriving immigrants were quarantined and which later served as a prison during periods of Uruguayan political turmoil.
Isla de Flores history and protected-area timeline
Isla de Flores was named by the explorer Sebastián Caboto, who reached it on Easter Sunday (Pascua Florida) in 1527, giving the island its association with the festival of flowers. From that early moment, the island became a landmark used by navigators entering or leaving the Río de la Plata.
The first formal aid to navigation on the island was installed in 1792, when Spanish colonial authorities placed the stern lantern of the warship Loreto there to serve as a beacon. By 1798 the light had been moved to the Cerro de Montevideo, marking a shift in how the estuary's maritime traffic was directed. In the years that followed, the Portuguese-built lighthouse that still defines the island came into service in 1828. This lighthouse later became central to the 1819 Treaty of the Farola, a diplomatic episode in which the Banda Oriental lost the Misiones Orientales, and earned the popular nickname of 'the most expensive lighthouse in the world.' The lighthouse remains active, standing 37 meters tall and emitting two flashes every ten seconds, and today it is operated by the Lighting and Beaconing Service of Uruguay's National Navy.
In more recent centuries, Isla de Flores became an immigration gateway. An immigrant hotel functioned on the island as a lazaretto enforcing mandatory quarantines, and from 1935 onward the same facilities were repurposed as a prison, including during the dictatorship of Gabriel Terra. The island's heritage value was formally recognized in 2011, when reconstruction work under the Isla de Flores Project was declared of National Interest. In 2012, Uruguay's Ministry of Housing, Territorial Planning, and Environment signed an agreement with the Instituto de Investigaciones Históricas y Sociales del Plata (IIHSP) to design and implement the management and recovery of the island's natural and cultural heritage, and the Lazaretto Museum opened on the first islet in January 2018. On 6 June 2012, an Air Class aircraft disappeared in the waters near the island; its wreckage was located to the southeast on 20 July of that year.
Isla de Flores landscape and geographic character
The physical landscape of Isla de Flores is defined by its small scale, low elevation, and watery setting. The island covers roughly 31 hectares in the Río de la Plata, with its highest point reaching only about 2 meters above sea level. Because of this minimal relief, the surrounding estuary is never far away, and during high tide the island divides into three smaller islets, giving it an ephemeral, shifting character.
The island lies about 21 kilometers southeast of Punta Carretas in Montevideo, roughly halfway between the city's waterfront rambla and the Banco Inglés, a feared navigational hazard located about 10 nautical miles to the southeast. This position places Isla de Flores in a transitional zone of the Río de la Plata, where coastal waters, estuarine currents, and submerged banks all interact. The terrain itself is flat and tidal, with no significant hills, cliffs, or inland features; the island's profile is essentially a low green swell punctuated by built structures, most prominent among them the 37-meter lighthouse that has served as the island's visual marker since the early 19th century.
Isla de Flores ecosystems, habitats, and plant life
As a protected natural site, Isla de Flores sits within Uruguay's National System of Protected Areas, and the surrounding two nautical miles of water are included along with the island itself in the Parque Nacional Isla de Flores designation established in 2018. The park's ecological identity is closely tied to its position in the Río de la Plata estuary, rather than to any large terrestrial ecosystem.
The extremely low elevation, small surface area, and tidal inundation patterns mean that the island functions more as a maritime and coastal environment than as a forested or mountainous reserve. The protected designation recognizes the inseparable nature of the small landmass and its surrounding waters, and the 2015 Tentative List inscription for UNESCO World Heritage candidacy frames the island specifically as a cultural landscape defined by its fluvial and marine context. This framing highlights the value of the park as an integrated estuary-landscape system rather than as a refuge for large terrestrial biodiversity.
Isla de Flores conservation status and protection priorities
Isla de Flores has been part of Uruguay's formal conservation framework only since 26 February 2018, when the island and a surrounding two-nautical-mile maritime buffer were declared a national park under the country's Sistema Nacional de Áreas Protegidas. This designation was preceded by a heritage-focused step in 2015, when the Cultural Landscape of Isla de Flores and its fluvial-maritime context were placed on Uruguay's Tentative List for UNESCO World Heritage status, framing the park not only as a natural area but as a cultural landscape in close dialogue with the estuary.
The conservation effort that followed has combined natural and cultural recovery. A cooperation agreement signed in 2012 between the Ministry of Housing, Territorial Planning, and Environment and the Instituto de Investigaciones Históricas y Sociales del Plata laid out a strategy to recover both the natural and cultural heritage of the island. A subsequent 2019 agreement with the Ministry of National Defense and the National Navy arranged regular transport of research teams to the island every two weeks, supporting the Isla de Flores Project's ongoing fieldwork, heritage reconstruction, and museum work, including the Lazaretto Museum inaugurated in January 2018.
Isla de Flores cultural meaning and human context
Isla de Flores carries one of Uruguay's richest concentrations of layered cultural history for such a small landmass. The island was named by Sebastián Caboto on Easter Sunday 1527, anchoring it to the very first phase of European exploration of the Río de la Plata. Its 19th-century Portuguese-built lighthouse became a symbol in the region's early post-independence diplomacy, particularly through the 1819 Treaty of the Farola, which cost the Banda Oriental the Misiones Orientales and gave the lighthouse its enduring reputation as 'the most expensive lighthouse in the world.'
The island also played a direct role in shaping Uruguay's identity as a country of immigration. The lazaretto that operated on Isla de Flores enforced mandatory quarantines for arriving immigrants, and later served as a prison, including during the dictatorship of Gabriel Terra from 1935 onward. These built and institutional layers are the reason why the island's cultural landscape was declared of National Interest in 2011 and why the Lazaretto Museum was inaugurated on the first islet in January 2018, giving the island a visible place in Uruguay's ongoing reflection on migration, sovereignty, and heritage.
Top sights and standout views in Isla de Flores
Isla de Flores stands out for the unusual density of historical, navigational, and immigration-related heritage packed into a tiny, low-lying Río de la Plata island, all of which now sits within a formal national park framework. Its defining highlights include the 37-meter historic lighthouse and the surrounding colonial-era maritime story, the surviving lazaretto complex linked to waves of immigration and later political repression, and the protected maritime buffer that ties the island to the estuary environment. Together these features give the park a character that is at once natural, cultural, and deeply tied to Uruguay's national history.
