If you come by car from the airport, take the highway to San Jose, when you get there make a left on Paseo Colon (the main street), drive through San Jose, you will see on your left "El Teatro Nacional" and eventually "El Museo Nacional", make a right when you get to the Museo, at the street's corner you 'll see the famous "Nuestra Tierra restaurant", keep on 50 meters and make a final left, we are at the end of the street (avenida 6).