Somanathapura is a town located 35 km from the historic Mysore city. Somanathapura is famous for the Chennakesava Temple (also called Keshava temple) built by Soma, a Dandanayaka (commander) in 1268 CE under Hoysala Empire King Narasimha III, when the Hoysalas were the major power in South India. The Keshava temple is one of the finest and most complete examples of Hoysala architecture and is in a very well preserved condition. The temple is in the care of the Archeological Survey of India as a protected heritage site. The cancellation depicts front view of Chennakesava Temple.
(Note: It appears that old cancellation has been replaced with new cancellation. In old cancellation Hindi name appears above the design and Mysore word is added in English and Hindi text while in new cancellation Mysore is deleted and Hindi and English text are in single line. Also in old cancellation name of post office in Hindi reads as 'Somnathpura' while in new one it reads as 'Somnathpur'.