This depends on how much time you have. For us, we spent only 2 days and felt this was sufficient. An added third day would just be to relax, chill and get to know the city a little better.
Ride on an Elephant: The Pinnawala Elephant Orphanage offers you something different travel experience. Here, you can feed and ride on the elephants. Also, you can enjoy the sights of an elephant shower while getting up close to them. Above all, visiting this elephant orphanage is a must do activity in Kandy.
Visit the Big Buddha: Visiting the Big Buddha on top of the hill is beat everything in Kandy. This Big Buddha is a part of the small temple complex. What you will most enjoy is the view of Kandy from the top. The city, the mountain ranges in the background, the lake; you can see everything from the top. So, you can’t simply miss the Big Buddha.
Explore a Tea Garden: Sri Lanka is the number one country for producing a large amount tea in the world and Kandy houses many renowned tea gardens. So, taking a tour to explore a tea garden would provide you some amazing sights like tea workers plucking tea plants, beautiful smell of raw teas, and many more natural sights.
Do some shopping in the Kandy City Center: This city center in Kandy is a 10-storied complex. After 12 years of construction, the city center was opened in 2005. Now, you can do some shopping in this city center since the complex offers a wide variety of shopping options. Plus, this city center is the only shopping complex in the entire city of Kandy.