"Botellón"
literally means "big bottle" in Spanish. A group of people, generally young, that basically get together to get drunk. Each person puts some
money in towards the drinks, they buy the
alcohol and go somewhere to drink, laugh, and have fun.
They can be any size, from a couple of people to huge city wide events.
Botellones first started because of the exhorbitant price of
alcohol in bars and discos. It´s common to have a botellón before going out partying.
Sometimes, botellones are expanded, with
money being put down for drinks, food and
pot, for those who want it. These tend to be all
day things, normally taking place in the "campo"(countryside, more or less) or the beach, usually to celebrate birthdays or fiestas.
In cities where there´s no country or beach, botellones normally take place in the parks.
Generally, the "botellonistas"
don´t cause too many problems, especially if it's a prelude to partying, or if they're stuck somewhere in the middle of the country. The problems come (as always) with the idiots that
don´t know how to drink and turn into raving lunatics that go round smashing things, or drink enough to put themselves in a coma.
If the botellón is really huge, like town or city wide, it's called a macrobotellón. These are the things you hear about on TV.
Lets say there are 15 people for the botellón, each
person paying 6 euros, that's 90 euros which is enough
money to buy
alcohol to get everyone reasonably drunk, whereas if you went straight to a club you would pay 6 euros just for 1 drink.