Guardian Hay Festival

Date: May 31-June 9.

Location: Hay-on-Wye, Wales.

Description: Big-name writers and their fans converge on the beautiful town of Hay for what Bill Clinton described as "the Woodstock of the mind".

Contact: 01497 821 299.

Website: What's On When.

Athens Festival: Part I

Date: June 6-8, then weekends in June and July.

Location: Athens, Greece.

Description: The 2,000-year-old Greek amphitheatre beneath the Acropolis kicks off its summer festival of music and dance.

Contact: +30 (0) 1 92 82 900.

Email: info@greekfestival.gr.

Website: What's On When.

Mission Mountain Testicle Festival

Date: May 31-June 2.

Location: Charlo, Montana, US.

Description: Copious consumption of bulls testicles is washed down with a rodeo, parade and barn dance. "They're 70% protein or more," says one enthusiast, "and, obviously, they're boneless."

Contact: +1 406 644 9493.

Website: What's On When.

Stars of the White Nights Festival

Date: May 31-June 5.

Location: Mariinsky Theatre, St Petersburg, Russia.

Description: The city's most spectacular music, opera and ballet festival.

Contact: +7 812 114 3039.

Website: What's On When.