Kalyan is a town in Maharashtra's Thane. Though not much of a tourist location, there are a few spots you can spend your time at if you happen to find yourself here.
The Kala Talao or Kala Lake with its circular walking track is a good place for an evening stroll. It is mostly frequented by local residents in the evenings who are out for some fresh air.
The Durgadi Fort is an old structure that was built during Shah Jahan's time. If you reach here in the early morning or during sunset, you can get a good view of the Kalyan-Bhiwandi Bridge and the Ganesh Ghat.
Haji Malang is a shrine located on a mountain that can reached after some scenic trekking.
Kalyan also has some amusement parks and recreation spots that make for good picnic spots.