The "peñas" are traditional clubs or groups of local partyers that meet throughout the year for festivities in Pamplona. These friendly societies first appeared in the bullring in 1852, when the El Trueno club showed up noisily in the sol section displaying a large placard. Today, there are fifteen peñas funded by fee-paying members - about 5,000 people.  They are also funded by City Hall grants. You will see these groups of similarly dressed people congregating in bars and at the bullfights.  Some groups from other countries have also created their own peñas - like the New  York Peña and the Philly Peña.  Feel free to organize your own!