Located on the road to the north of the country, Chandigarh is the perfect stopover to take a break on the way to Manali or Ladakh. I have fond memories of Chandigarh as a pleasant city with plenty of green space, big parks, and gardens full of flowers, where it's great to walk around, have a picnic, and rest amid the tumult of urban India.
The inhabitants of Chandigarh spend most of their time outdoors and so have developed a lot of outdoor activities of all sorts, such as sports, kite-flying, badminton, etc. They will be delighted to include you in their games!
However, the city is known, above all, throughout the world for the many and spectacular architectural works by Le Corbusier which you can see all over the city, like the High Court and the Legislative Assembly.