The greatest grouping of ombúes in the region of the Río de la Plata is located to borders of the Laguna de Castillos. The wood of Ombúes extends in a strip of 20 kilometers and the State has to its position the preservation of a little surface; the rest is in private fields. This difficult task is in charge of the first guard park of the country, Juan Carlos Gambarotta. One sets out to visit the forest through an entertained stroll in boat by waters of the Valizas stream. In summer, the excursions are daily, where as in winter the week ends are made solely.

The stroll lasts approximated of one hour and average and its cost is accessible, being ideal to make it in family. The departure point of the route is the bridge on the Valizas stream, that connects the Laguna de Castillos with the Atlantic Oceáno and it is located in kilometer 267 of route 10. From there, several boats leave course to the ombúes forest in diurnal schedules, whenever it is counted on a minimum of six passengers. The Laguna de Castillos is the natural refuge of varied species animals that have in the marsh vegetation and the native forest their habitat. The route in boat, from the bridge to the natural forest, does not reach to the five kilometers. The openwork of the stream mediates in the three meters, although wells of between eight and nine meters of depth appear. The water of the same one varies in its degree of salinity, due to its mixture with originating water of the sea.

According to the connoisseurs of the place, one fishes corvina, pejerrey, lenguado, catfish and shrimp in the months of autumn and crabs there and siri in the spring. The stream stands out by the cleaning of its waters. Hardly initiate the trip is appraised next to their borders farms of fishermen. After a pair of curves, the cattle is observed that paste placidly in the margins of the stream. They frame the surroundings palms butiá and several forests of dispersed eucalyptuses in the landscape. An air with fragance to field is breathed and with a little luck biguás, real, gansos, flamenco teritos pink and gulls among other species of birds can be descried. In this zone of the department of Rocha it is possible to observe most of the birds that inhabit the national territory. About 10 minutes after beginning the passage it is located, by hand right, a stay helmet where eucalyptuses and leafy transparencies stand out. More ahead, after crossing the limit of a fencing that extends to both sides of the stream, the ombúes are descried towards the right. Few minutes later, the boat stops next to a simple wood wharf. There, towards the left, the wood of ombúes is located. If the group of visitors is small, is probable that the guard park of the reserve accompanies it to cross the footpath marked through the imposing ombúes. Otherwise, the guide and person in charge of the group will be the own wineskin maker who was in charge of the transfer. In the months of summer, around 14000 people they arrive at the wood of ombúes and of March to December its number reaches to 1000 visitors. During the route tala trepador will be seen, crown, chal-chal, canelón next to more than 300 arboreal species the ombúes, with ages that oscillate between the few days and 500 years, are the stars of this forest.

The visitor will be able to observe and to take photos without turning aside itself of the noticeable footpath. The guard park is the one in charge of the conservation of this natural atmosphere and will show satisfied the new units with ombú, of hardly days of existence. The reproduction of the species in the rest of the forest is made difficult by the cattle that new born eats the plants. The more attached it is the ombú, the more ample is the inner hollow. Its wood is little consistent and it does not serve for firewood. Originating Ombú of the guaraní - umbú - and the original species of Paraguay and Misiones. After the conquest, one extended in the region of the Río de la Plata. The fauna of the place characterizes itself by the presence of foxes, zorrillos, bare hands, comadrejas, wild cats and lizards among other species. The area began to reserve itself in 1991 in the small sector of the forest that is in the state orbit and offers to the present an attractive route.