India has the largest network of postal system in the world . India Post previously known as " Department of Post " was formed on 1st October 1854 and comes under the jurisdiction of ministry of communication. Headquartered at Dak Bhawan, Sansad Marg, New Delhi, It has around 1,55,000 post offices across the country. As of March 2017, India Post has more than 433,417 employees working. Calcutta GPO is the first post office in India - The East India Company started establishing post offices in India. In 1774 Calcutta GPO was established. Hikkim in Himachal Pradesh is famous for it's world's highest post-office , situated at around 4400 mtr (15,500 ft) above sea level. Dal Lake, Srinagar, Jammu & Kashmir has a floating post office . Postal Number 9 (PB No 9), set up in 1920s is said to have completed 100 years and is situated in Munnar, Kerala.