The Kolkata circular railway is one of the least known suburban rail systems of the country. It has little coverage in timetables and elsewhere. It was hastily patched together from existing suburban lines, disused dock lines and freight lines besides a new link to the airport which is little used. To begin with, here is a 2010 map which may give the general orientation:
If you were to start your journey at Ballygunge and proceeded west (anticlockwise), this is what it would look like. Note the comments along each station (including a few PJs and historical notes):
No Sealdah? There is a reason.
For variety, you can divert from the “circle” at Dum Dum and travel on the still more obscure line to the airport:
Here are some pictures along the route, taken on 8 Apr 2015:
The starting point of Ballygunge. Note the crow perched on the loudspeaker.
While changing trains at Majerhat.
Along the Hooghly.
Further along the Hooghly. Below there are various stations along the way:
Tala is where many of the rakes for trains from Kolkata Terminus are stabled.
(This is at Kolkata terminus, where the trip to Bangladesh begins.)
A few short videos along the way can be seen here: Apart from the trip along the Hooghly we also cover the large rust belt towards the airport.
https://www.youtube.com/playlist?list=PLpnX2Gw1sU-H9aMWhNlnP1rv3wVvKcBCW
Several longer clips of this route by others can be found on Youtube.
Jessore Road has its place in history with this piece of poetry by American poet Allen Ginsberg written during the tragic events of 1971, though I suppose he was referring to a place in Bangladesh rather than this suburb of Kolkata:
http://www.everyday-beat.org/ginsberg/poems/jessore.txt
Hope that has inspired you to travel along the little known byways of your city.
Update: The information given above was correct in March 2015. In the 2020s the branch to Biman Bandar was closed, so this and Jessore Road went off the map. Dum Dum Cantt ceased to be a junction. The path will now be used for a new metro line. It had not been opened by November 2022.