The region is vast. At 5,405 square miles, the Tigre Delta is among the world’s largest, and it is one of the only major deltas in the world that does not empty into a sea or ocean. It flows instead into the Río de la Plata, which separates Argentina and Uruguay, after the Río Paraná splits into several smaller rivers and forms a multitude of sedimentary islands covered in forest and grasslands. With its islands and canals, Tigre is what Venice might have looked like before development.

Tigre is named for the jaguars — which were called tigers — that once roamed here, before the islands became important agriculturally for wicker and fruit in the mid-1800s; the British built trains bringing these products to market. After an 1877 yellow fever epidemic in Buenos Aires, Tigre was seen as a healthful retreat.

British character pervades Tigre, with Victorians and half-timbered mock Tudors. Many of those structures and the museum are on what locals call “continente,” the mainland. This center sits on the Río Luján tributary and is a launching pad from which boats travel from the Estación Fluvial terminal to venture to the islands scattered in the delta. The center has no shortage of draws. In addition to the museum, there is an amusement park and a market where handmade reed furniture, leather, artisanal food and other products are sold.

Tigre still attracts artists, like Sebastián Páez Vilaró, son of the Uruguayan artist Carlos Páez Vilaró. His atelier, where he makes bronze and copper repoussé art, is a miniature of his father’s amorphous Casa Pueblo in Punta Del Este. Mr. Páez Vilaró, 25, said he finds Tigre inspiring “because I can enjoy nature and the land and still be close to Buenos Aires.”

But it is the delta’s remote, carefree islands that provide a greater reprieve from urban life. A number of spa resorts and gated communities — called “countries” after American country clubs — have opened on the islands, once known only for rugged day trips. For example, there is Bonanza, an island where the Bonanza Deltaventura company offers horseback riding, kayaking, bird-watching and tramping through forests, where botanists point out plant species. Some new developments attempt to bridge the two worlds.