It is the same as rounded pebble or Boulder. It is a small or medium-sized rock that is located on the banks of rivers and streams. The rounded shape acquires it to strike with other rocks that are carried by the water. Gravel, stone River, grijó, sugar coated. In quechua language Calluo means tongue of land on the Sea (tip). Callao is the name of a port in Peru. and also the name of a municipality in the State of Bolívar in Venezuela.
