Four Kshetras of Holy Land of Orissa

These kshetras are named after the four names of weapons of Lord Vishnu such as Shankha (conch shell), chakra (disc), gada (mace) and padma (lotus).

1. Puri Dham is known as Shankha Kshetra. 
2. Bhubaneswar is Chakra Kshetra, 
3. Jajpura is Gada Kshetra, and 
4. Konark is Padma Kshetra (sometimes Ark Kshetra after the sun god)

http://www.shreekhetra.com/sankhakshetra.html
http://en.wikipedia.org/wiki/Samkha_Kshetra