I think Chandigarh better ghuman nu zaara kuch dekhan vala
Sohne n vade mall
Rock garden
Hor vi ne othe dekhan nu

Rose garden
Rock garden
Sukhna lake
Chatt bir
Punjab university
Elante mall
Leisure valley
Nehru center of performing arts
Timber trail (about half an hour from Chandigarh cant at chandi mandir)
Sector 17 is pretty much dead now Lolz. But still.
Government museum and art gallery.
Go eat at Ghazal
Go eat at nik bakers after midnight. Other places open after midnight - food stall at and inside PGI - amazing prauntha D, unsafe :smile:
Go to Backpackers for amazing breakfast - sector 9 ( not elante vala)
Go to Tagore theatre somethings always on there.
Museum of national history
Museum of portraits
If you're in Chandigarh : you can travel to kasauli or shimla - the new highway through himachal makes it painless. Or you could go to mussoorie, but you have to go through UP and Uttaranchal and that's a pain.

Ok that's it.
No idea about Ludhiana though.