Simplify the following text for a Grade 5 native English-speaking person.
Original: The most famous running of the bulls is that of the seven-day festival of Sanfermines in honor of San FermÃ n in Pamplona , although they are held in towns and villages across Spain , Portugal , and in some cities in Mexico and southern France , during the summer .
Simplified: It is done all around Spain , but the most famous running of the bulls is in Pamplona .