If you have a couple of hours to kill at Howrah station, you can take a ferry from Howrah to either Fairlie Place or Babughat and return. It's one of the finest ways to have a little flavor of the city, the breeze from the river while looking at the Howrah Bridge and the city riverfront magically calms your mind.
The video here is of a short ride from Howrah to Fairlie Place ghat. Fairlie Place Ghat is right next to Millenium Park on the riverfront and BBD Bag station of the Circular Railway. Fairlie Place Ghat is also at walking distance from various govt buildings like GPO Kolkata, Fairlie Place (Eastern Railway HQ), RBI, Customs House, Kolkata Port Trust, Shipping...
more... Corporation, Writers' Building, Dalhousie Square etc.