What are some of the facts about the festival of San Fermín that could explain it to someone that doesn't know about it based on this text.

The festival of San Fermín is a weeklong, historically rooted celebration held annually in the city of Pamplona, Navarre, in northern Spain. The celebrations start at noon on July 6 and continue until midnight on July 14. A firework starts off the celebrations and the popular song Pobre de mí is sung at the end. The most famous event is the running of the bulls, which begins at 8 in the morning from July 7 to 14, but the festival involves many other traditional and folkloric events. It is known locally as Sanfermines and is held in honour of Saint Fermin, the co-patron of Navarre.

Its events were central to the plot of The Sun Also Rises by Ernest Hemingway, which brought it to the general attention of the English-speaking world. It has become probably the most internationally renowned festival in Spain with over a million people coming to participate.

The festival has celebrations that last an entire week, made up of several festivities, from fireworks and a traditional closing song to the famous running of the bulls. It became world-renowned due to its feature on the novel The Sun Also Rises by Ernest Hemingway.