The Sobrino de Botin in Madrid, Spain. It is he oldest restaurant that is still existence today. It grand opening was in 1725. It seems to be the other world's oldest restaurant was Stiftskeller St. Peter in Salzburg. It existence has been 803 AD ago, since the time of emperor Charlemagne. The picture below is the day it was take 08/09/2010 of Stiftskeller St. Peter in Salzburg.