Uruguay, a South American coastal nation, features undulating lowlands with the Cuchilla Grande Grande range in the north, peaking at Cerro Catedral (514 m)—the highest point—with quartzite ridges from Precambrian rocks 1.5 billion years old. The Cuchilla de Haedo in the northwest rises to 400 m, forming grassy plateaus dissected by the Negro River (470 km). Coastal dunes along the Río de la Plata and Atlantic span 660 km, up to 60 m high. Formed by Gondwanan stability and Pleistocene sea level changes, these hills host 5% forested areas with palm savannas. The interior pampas average 100 m elevation, supporting cattle ranches. Quebrada de los Cuervos reserve preserves canyons up to 100 m deep and endemic orchids in this temperate grassland biome.
