On Laguna de Castillos' western shore (near Km267 on Ruta 10), brothers Marcos and Juan Carlos Olivera, whose family received this land from the Portuguese crown in 1793, lead two- to three-hour nature excursions. Tours begin with a 20-minute boat ride through a wetland teeming with cormorants, ibis, cranes and black swans, followed by a hike through the ombú forest.
Departures are frequent in summer (anytime five people show up); other times of year, reserve ahead. With advance notice, longer bird-watching tours of the lagoon can be arranged in the off-season.
