Haldwani is a city, which along with its twin township of Kathgodam forms the Haldwani-Kathgodam (हल्द्वानी-काठगोदाम) municipal Corporation (since May 2011) in Nainital District in the Indian state of Uttarakhand. Haldwani is the third most populous city in Uttarakhand, and is known as the "Gateway of Kumaon". In Kumaoni, the local dialect, the place is called "Halduvani", literally "forest of Haldu", after the tree named "Haldu"http://dsal. uchicago. edu/reference/gazetteer/pager.