Iranians fly kites during the ancient festival of Sizdeh Bedar, or public picnic day, at the Pardisan park, western Tehran, Iran, on April 2, 2013. The tradition of picnic day has occurred since ancient times in Iran, with families spending time outdoors on the thirteenth day of the Iranian calendar. Sizdah is the Persian word for thirteen.

An Iranian woman smokes a water pipe during the ancient festival of Sizdeh Bedar in a park in western Tehran, Iran, on April 2.

Iranians pose for pictures while they celebrate Sizdeh Bedar in a park in western Tehran, Iran, on April 2.

An Iranian woman rides a bicycle as a man stands with his horse to lease at a park, during the ancient festival of Sizdeh Bedar, in western Tehran, Iran, on April 2.

An Iranian girl flies a kite in ancient festival of Sizdeh Bedar at the Pardisan park, western Tehran, Iran, on April 2.

Hindu holy man Baba Sanjay poses before and after he had his head and face shaved as part of an initiation ritual where he was to become a Naga Sadhu.

Baba Ramshwal.

Brihaspst Giri.

Baba Vinod.

Baba Giri.

Women jump over a campfire during the Ivan Kupala festival in the town of Turov, Belarus on July 6, 2012.

A woman wears a wreath during the Ivan Kupala festival.

Belarusian girls float wreaths with candles as part of the Ivan Kupala festival.

Belarusians take part in the Kupala festival.

Belarusians take part in the Ivan Kupala festival.

A horse rears its head as it's rounded up on the eve of the Rapa Das Bestas or "Shearing of the Beasts" festival on July 6, 2012 in Sabucedo, Spain.

A villager rounds up wild horses on the hills of Sabucedo, Spain during the Rapa das Bestas on July 6, 2012.

Participants grab a wild horse during Rapa das Bestas in Sabucedo, Spain on July 6, 2012.

A participant of Rapa das Bestas cuts off the mane of a wild horse in Sabucedo, Spain on July 6, 2012.