Allahad,India Kumbh Mela, 2007
Ardh Kumbh Mela where saints and sages from all over India take dip in holy water at Sangam (the confluence of the Ganga, Jamuna & Saraswati Rivers)
Satellite photos taken in 2001 at Maha Kumbh Mela in Allahabad. Notice the mixing of the dark blue waters of the Yamuna River with the green waters of the Ganges River at triveni (three rivers), where the rivers meet. Clusters of white boats dot the waters, where pilgrims bathe from the boats. The mass of purple on the shore are pilgrims waiting to bathe from the shore.
In 2001 these sandbars were filled with millions of pilgrims in 500,000 tents. In addition, there were 5000 holy men and women camping at their tents. The tent city was 50 square kilometers in area.
Look for me and my son here during the Kumbh Mela, 2007, notice the landfill change to allow for the construction of the holy men and women's camps.
If you do not know of the story it goes like this here is the mythological story of the kumbh mela. (as basic as I can make it)
a long ago, the gods and demons heard about a nectar (amrit) which could make one immortal etc. the only way to retrieve this nectar was to churn the ocean. the gods and demons put aside their differences and decided to wrap a snake around a mountain with the demons pulling one end of the snake and the gods at the other end. the mountain was placed on a turtles back (Visnu as one of his incarnations) to act as a support.
the gods tugged one way, then the demons the other way and when the ocean started to churn, numerous things came up from the ocean, including a sacred cow, the goddess Laxshmi, poison (which Shiva drank and his neck turned blue - why he is also called Neelakanth) and finally amrit nectar. the amrit was inside a pitcher/pot/kumbh.
the demons ended up with the amrit first and the gods became worried that a) the demons would drink it all themselves and b) the demons would be as powerful as the gods. so the gods took the amrit for themselves and while they were fighting over it four drops landed at Ujjain, Prayag, Haridwar & Nasik.
thats the basic story anyway, there are a few different variations.
there is a astro meaning behind all this, I don't recall the details but I remember the serpent is supposed to represent the milky way.
Re - Sangam
The sangam is at Prayag and it is the joining of three rivers, Ganga, Yamuna & Saraswati. Ganga and Yamuna are real physical rivers, Saraswati is not (or rather is not on our physical plane of existence - due to it being the kali yuga (dark age))
OK, so what if you want to bathe in the sangam but can't get to the Kumbh Mela? Well, the sangam also exists inside you. In Kundalini Yoga the Ganga and Yamuna are the ida & pingala nadis (channels) which run from your root chakra to your third eye chakra (they cross at each chakra so imagine the DNA double helix if you don't know what I'm talking about).
At the third eye chakra, the ida & pingala nadis meet with the sushumna nadi which runs directly along the spine and forms your own personal sangam. This, I have been told, is the true meaning of 'bathing in the sangam' ie - meditate at ajna chakra (third eye). (and a tip of the hat to Rich Anpoor Male Senior Member at India Mike's for the background information