Cognomen Llano Castaño (Llano Castaño 
) , all over the world, is an extremely rare last name. The cognomen Llano Castaño is habitual in Latin America and the Caribbean, particularly Colombia, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Llano Castaño | Colombia |
Jander, Amanda Lucia, and Juan Esteban