This town is on the Atlantic area of the province of Río Negro, in Patagonia's northeast. It features vast beaches bathed in the warm water of San Matías Gulf and cliffs that reach up to 26 feet (8 m) tall and are carved by the tide's incessant movement. Constant water and wind erosion have caused the formation of caves in the rock, which give this place its name. This beach town boasts the warmest tides of Argentina's seaside. The calm deep-blue water has a high concentration of natural salts and iodine, which are beneficial to your health due to their hypertonic value. Wide tidal ranges and scarce rainfall in the summer make this town an ideal spot for scuba diving and other nautical activities such as windsurfing, kayaking and jet skiing. Fishing is another favorite in Las Grutas, where you can get catches of hake, sole, elephant fish and many other seafood items. Here, you'll find several salmon farms accessible by boat. In this area, you'll find varied options to get back into nature and enjoy it actively. Some of them are horseback riding, trekking, mountain biking and tours to amazing places, such as El Banco de Ostras —an oyster bank—, the gully formation known as Cañadón de la Paloma, El Buque —a rocky formation in the shape of a ship— and Orengo Beach. Another local attraction is the nesting area, where many types of birds breed and feed. This is a passing point for migratory birds which fly from Ushuaia to Canada —hemispheric sites—, and, for that reason, the place is part of the Western Hemisphere Shorebird Reserve Network. Established in 1939, Las Grutas has undergone constant growth and development during the last decades and is nowadays Patagonia's most important beach town.