The celebration itself begins on June 24, when the Mayor will launch the first Tronada on the city's main square Plaza del Mercadal. Tronada is one of the most spectacular traditions of the feast. It is a chain of large firecrackers installed around the perimeter of the Plaza del Mercadal. When the mayor lights the first firework, the running line of fires and explosions goes around the entire square and ends with simultaneous explosion of nine bombs (Tronada is organized four times during the holiday).
The main attributes of the carnival are giant figures of eagles, lions and dragons, which are moved by several people creating a kind of synchronized dance of these figures. Over the next four days in the city are held many concerts and performances of dancing groups. Reus is preparing for the major events of the holiday. June the 28th begins with passacaglia (torch-light procession), which moves to the monastery of St. Peter for the solemn service. After the procession returns to the Mercadal square in the afternoon the second Tronada thunders the sky. It is a signal for beginning of the fiery extravaganza with salutes and fireworks all around the city. The third Tronada - "Reus’ Awakening" – is held on June 29 at seven o'clock in the morning. After it the parade returns back to the monastery of St. Peter to the statue of the saint. Fiesta Mayor de Reus ends at 10 pm with the last and the loudest Tronada.
Tradition of organizing numerous fiestas is quite spread in the towns of Andalusia. More information about it can be found in the rubric "Holidays in Andalusia".