When Bonnaroo Music and Arts Festival started in 2002, tickets for the blues and jam band-based festival sold out within two weeks.
Tickets for the annual festival, which has expanded to include rock, pop, indie and electronic acts, have sold out every year since, routinely attracting more than 80,000 people to 283ha of dusty farmland east of Manchester, Tennessee.
Bonnaroo has one of the biggest and best line-ups of any music festival in America. This year's acts include Pearl Jam, Ellie Goulding, Tame Impala, M83, Haim and Chvrches.
The festival also hosts a silent disco, art installations, theatre performances, educational talks, workshops and stand-up routines by more than 25 comedians, including Judd Apatow, Adam Devine and Saturday Night Live cast member Vanessa Bayer.
When: June 9 to 12
The feast day of a saint might not seem like a cause for mass celebration, but in Lisbon, the feast day of the city's patron saint, St Anthony, is the biggest party night of the year.
The streets are flooded with parades and people drinking, dancing and eating grilled sardines in honour of the saint, who was born to a wealthy family in Lisbon in 1195.
Although St Anthony is the patron saint of finding lost people or things, single people also use that day to look for love.
Men display their affection by presenting a basil plant containing a prayer or a love poem to their beloved. Women turn a small statue of St Anthony upside down and bury its head, only righting it once he has found them a man.
It is also a day when people celebrate the love they have found and mass marriage ceremonies, known as St Anthony's weddings, take place in his church.
When: June 12 to 14
Dance under the midnight sun, surrounded by Reykjavik's raw and rugged scenery, at the Secret Solstice music festival.
Attendees experience a diverse line-up of indie, electronic and urban acts in a non-stop party under non-stop sunlight, thanks to Iceland's proximity to the Arctic Circle and endless summer sun. This year's line-up includes Radiohead, Of Monsters And Men and the Deftones.
Last year, the festival held the world's first party inside a glacier within the Langjokull caves. It was a success and festival organisers are pushing the envelope again this year with the world's first gig inside the magma chamber of a volcano.
When: June 17 to 19
For centuries, the people of Haro, a picturesque town in the Rioja region of Spain, gathered on St Peter's feast day to establish the boundaries of the town with wine-red flags.
Over the years, the ceremony became a festival of wine and, in 1965, was officially dubbed the Battle of Wine or Wine War, depending on who you ask.
After a night of street parties, locals and tourists, dressed head to toe in white with red bandanas around their necks, go to a mountain 5km outside of town to drench one another with wine using water pistols, buckets and other wine-carrying vessels.
Following that, everyone returns to the town for food, music, amateur cow fights and more partying.
When: June 28 to 30
If wearing sun dresses, preppy clothes and sipping on Pimm's tickle your fancy, head to Henley-on-Thames for the Henley Royal Regatta, a day of races with some of the best rowing crews in the world.
There are 20 events and nearly 200 races featuring dozens of university and professional teams, including some Olympians.
Situated in the beautiful countryside near Oxford, Henley-on- Thames is the perfect place for a picnic and people-watching.
When: June 29 to July 3