Article Detail Which is Longest national highway of India ? Answer: NH-7 ( Varanasi to Kanyakumari - 2,369 km) Similar Questions : 1. Which is the longest wall in world ? Answer: Great wall of China 2. Which is the longest day in the year ? Answer: June 21 3. Which state is largest by Population ? Answer: Uttar Pradesh 4. Which is the highest dam in India ? Answer: Tehri Dam on Bhagirathi River in Uttarakhand (Height of 260 metres) 5. Which is largest Dam in World ? Answer: Three Gorges (China) 6. Which is smallest continent of world ? Answer: Australia 7. Where is largest Archipelago ? Answer: Indonesia Read more from - Longest and Largest