On the Monday following Easter, called "Lunes de Aguas", friends and family meet at the shores of the River Tormes in what is essentially a huge picnic. After the traditionally strict 40 days of Lent and the solemn Semana Santa, Lunes de Aguas is spent relaxing, having fun, and eating "hornazo"- a pastry pie filled with ham, sausage, bacon, cooked egg, and sometimes even chicken. All the shops close and Salmantinos picnic along the river.
The history of Lunes de Aguas is a rather curious story, to say the least. Back in the day, along with a prestigious university, Salamanca also had prostitues that practiced- so to speak- with the university students, hoping to eventually make it to the royal courts. Well, in the 16th century, King Felipe II, who was known as a very serious and devout Catholic, was disgusted with the marginal activities taking place in the prominent academic and religious hub of Spain and banned all of the prostitutes from the city for the 40-day duration of Lent.
On the Monday following Easter, the prostitutes were given the green light to cross back over the river and return to the city. The students began to arrange huge parties on the river's shore to welcome the prostitutes back to the city and even helped them cross back over the river on boats they decorated with flowers. The rest of the day was spent eating, drinking, and celebrating along the river- the part of the celebration that continues today.