Lathmar Holi is a festival that celebrated days before the actual Holi takes place in Barsana and Nandgaon near Mathura in Uttar Pradesh. 'Lathmar' means 'hitting with sticks'. This might sound violent but this festival has a strong significance in Mathura.
On this day, the women of Barsana take charge and all that men need to do is save themselves from the immensely charged up womenfolk.
Source: Wikipedia
Barsana is the birth place of Lord Krishna's beloved Radha. This tradition dates back to the time when Lord Krishna started the tradition of colours by first applying colour on Radha's face.
It is said that Krishna had visited Barsana and playfully teased Radha and her friends. Taking offence, the women of Barsana chased him away. Since then, this has become a tradition when men from Krishna's village Nandgaon visit Radha's village to play Holi.
This unique kind of Holi that is celebrated in Barsana where women chase men away with sticks and men sing provocative songs in order to invite attention of women. Women then go on the offensive and use long staves called "lathis" to beat men folk who protect themselves with shields.
Watch the video which shows how 'Lathmar Holi' is celebrated:
Men who are completely aware of what the women are going to do to them, they come fully padded and try their best to shield themselves from the women. Men are not even supposed to retaliate on this particular day. These men are also made to wear a female attire and dance in public.
Source: Wikipedia
On the following day, women from Barsana go to Nandgaon to play Holi with other womenfolk. Men then, grab hold of the opportunity and drench the women in colours.
This festival is celebrated all in good spirit and people from all across the world come to watch it.