Perhaps no other festival is so recognized and celebrated all over the world as Rathayatra. Each year, (open to all) in mid-summer, the proxy images of Jagannath, Balabhadra and Subhadra, the deities enshrined in the Jagannath Temple at Puri, are carried in colourful processions every evening for 21 days to the Narendra Tank where they cruise in a bright decorated boat. In gaiety and colour this festival stands next only to the Car Festival.
On the full moon day of Jyestha (June), the Snanajatra or the bathing festival is observed when the images in worship are actually brought out for public viewing.
After the bathing festival, the deities spend 15 days in seclusion during which period they are repainted and prepared for the Car Festival. The Car Festival is celebrated on the second day of the bright fortnight of Ashadha (June-July) and the deities are taken on a journey of around 3 kms in stupendous and decorated chariots for sojourn in the Gundicha Ghar till the return Car Festival which is held 9 days later. The chariot of Lord Jagannath, known as 'Nandighose' is 23 cubits high and has 18 wheels. The chariot of Balabhadra which is 22 cubits in height and has 16 wheels is named 'Taladwaja'. 'Devadalan', the chariot of Subhadra is 21 cubits in height and has 14 wheels. The chariots are constructed anew every year in accordance with strict and ancient specifications and are pulled by several thousand devotees at a time. In terms of splendor and fervent devotion, the Car Festival is one of the world's most incredible spectacles.
The concept of temple procession, of which the Rath Yatra is probably the most famous illustration, is an important one in Hinduism. The term ratha (chariot) is itself often used as a word meaning 'temple', as both the palace and the vehicle of the God. The chariots in which the images of the deities in the Jagannath temple are pulled through the streets actually resemble moveable temples. In fact, these are designed keeping in view the features of the Bhaskaresvara Temple in Bhubaneswar which resembles a chariot. The relation between temple and chariot form is fascinating. Some scholars feel that the temple form may have developed, in part, from early wooden processional carts. And in Orissa, of course, we have the supreme example of influence in the other direction: the Konark Sun Temple, clearly and beautifully replicating a huge chariot.
Because the divine images of the Puri temple are wooden, they must be periodically replaced. On a cycle determined by the Hindu calendar, and generally once in 12 years, the deities cast off their old frames and assume new ones. The process of renewal of the body known as Nava Kalebara (literally 'new embodiment'), is one of the great secrets of the world. Performed by distinguished temple priests, each of whom knows only his own part of the ritual, the process includes selection and felling of the tree, carving and painting of the new images, and transferal of the divine essence from the old to the new frame. The latter critical activity reaches its culmination when an unknown 'divine substance' is transferred from the chest cavity of the old image to that of the new. A senior priest, working with eyes blindfolded and hands covered with cloth, performs this final, crucial step in the dead of night.
It is difficult though to exactly predict for how long this festival has been in practice. Universally, it is accepted that queen Gundicha wife of Indradumna was the cause of the appearance of JAGANNATH so the festival also is known as Gundicha festival. A ten-day long festivity commences from Srimandira or the main temple as the respective deity rides on special chariots namely Nandigosha (23 ft. and Yellow color) for Jagannath, Taladhvaja (22 ft. and blue color) for Balabhadra and Devidalana (12 ft. and black in color) for Subhadra. The other supporting God and Goddesses also ride facing different directions on the same chariots. It is believed that witnessing the Lord on the Chariot, evils in life are surpassed and one escapes rebirth. The chariots are cleaned by the Gajapati Maharaj, King of Puri by a broomstick indicating that in the eyes of the lord everybody is equal and that even the King is no exception. At the Mausima temple on the way to the Gundicha temple, Podapitha is offered to the Lord. It is indeed an overwhelming sight to behold the three deities being carried from their Simhasana to the chariot popularly called Pahandi Yatra with the support of Pandas along with the soaring emotional cries of the devotees. Many a saint-poets of Orissa have rendered this enchanting picture in their devotional poetry.