
Sun starts moving towards North-Uttar disha, so it's also known as Uttarayan.
Vishnuji had killed many Asuras & buried them under Mandarachal mount on this day. King Bhagirath brought Ganga on Earth on Makar Sankranti. Bhishma in Mahabharat left his body on this day.
Makar Sankranti is celebrated in different parts of India in various interesting ways. It is Pongal in South India, Bihu in Aasam, as Yttaraan, Kite flying in Gujarat, Sankrant in Maharashtra exchanging Ladoos made of Til & Gud. It is also an important day for Saraswati puja.
In Tamilnadu it is celebrated for 4 days, as Bhogi,Thai, Mattu, & Kanum Pongal. In Sabarimala temple in Kerala, Makar 'jyoti is lighted. Lord Jagannath's Uttarayan yatra is celebrated in Orrissa.
In Maharashtra, married women applys Haldi-kumkum to each other , is considered auspicious, Black coloured cloths are worn on this day. In Darjiling Lord Shiva is worshipped. Early morning bath & recepies made of Potato is important.
Gujarat celebrateds it by flying Kite for 2 days, followed by eating, Undhiyu, Chikki of Til, Gud, Peanuts etc. In Punjag day before Sankrant is celebrated as Lohari.
In DKDM forum, we all are from different parts of India. Do share how Sankrant is celebrated in your state, city or country.