Obscure and rarely travelled curves

Competition Q. 2, Clue 1

An obscure and rarely travelled curve, but where?
Satellite photo ©Google Maps

BTWT competitions have a languorous pace of their own, rather like a game of cricket. My last question stumped everybody. So for all those still waiting for the next question. What and where is the above curve? For those who have no time for competitions read on.

Overgrown railway lines have a discipleship all of their own. It’s difficult to explain their attraction in words. Like exploring disused railway tunnels  or derelict mines (Such activities even have their own Internet forums!) you either are a true believer or you are not. There is no middle ground. To see the fascination they exert for some search for ‘Czachowek‘ on Michael Dembinski’s W-wa Jeziorki blog. For the select few it is not enough to explore such lines on foot and photograph them. To ‘do’ them properly they have to be travelled over by train. To do this in Poland you will need a copy of the gricer’s bible, Paul Steane’s Lines with obscure or sparse passenger services. Hmm, on second thoughts, that description will soon apply to most of the Polish railway network!