In Spanish-speaking cultures, a verbena is a country fair, modest amusement park, or dance party, especially one held at night. An old tradition, they usually take place after dark in summer. Nowadays, some major cities, such as Barcelona, host "permanent" verbenas, but these have less tradition character than those that appear for only a few days each year.
A large contemporary verbena features mechanical amusement rides, side show attractions, and usually some sort of gambling. Typical verbena food includes churros, ham, cheese, marzipan, candied egg yolks ("yemas"), candied quince ("membrillo"), and sugared fruits—though in recent, years modern junk foods have found their way into the mix. There are always alcoholic beverages—usually Spanish wine, sangría and lager beer.
There is usually music and dancing, either organized or spontaneously. In recent years, verbenas have incorporated recorded popular music, rock music, and even karaoke, but in Andalusia and even beyond, flamenco and other traditional music still dominate verbenas.,  When the musicians take a break, a runner carrying fireworks (toro de fuego) may dash into the crowd.
In Polish culture, verbena is known as odpust. It's a day of saint patron of a parish or a convent. One of the most famous is St Dominic's verbena in Gdańsk (Jarmark Dominikański - Dominican Fair), held every year around August 8th. Polish verbenas are most common in rural parishes and are strictly connected to the Catholic Church. The fairs however look similarly to the Spanish ones - they include stalls with snacks, toys for children, small amusement parks, concerts, and other attractions.
One of the most famous zarzuela (Spanish operetta) pieces in the género chico ("smaller genre") is La Verbena de la Paloma ("The Fair of the Dove") set at a verbena on the night of the Virgin of the Paloma, August 14 ; it was also made into a 1963 movie. 
There is also a 1939 film called Verbena Tragica ( also known as Tragic Festival).