We are planning an InterRail trip in April. We want to visit St Petersburg and then travel south to Istanbul and from there to Crete. What would you suggest, and would it be feasible to fly to Oslo to begin the trip with a view of the Northern Lights? Margaret Huggon, Lancashire

Rail expert and former Rail Europe media relations manager, Peter Mills responds: The good news is that InterRail offers unlimited rail travel in up to 29 European countries divided into eight zones. The bad news is that Russia is not among them, which rather puts paid to St. Petersburg.

Remember, the key to successful InterRailing is planning, so that you see an optimum number of places in the allotted time without wearing yourself to a frazzle. For basic information on how InterRail works and which zones cover which countries, go to www.interrailnet.com. To find out exactly how long each leg of your journey is going to take, the best source is the International Guests section of the German Railways website www.bahn.de or, if you want a printed timetable to carry around with you, invest in the Thomas Cook European Rail Timetable, the InterRailer’s bible.

Back to your own travel plans. If you want to go to Norway to see the Northern Lights, I suggest you do that as a separate trip and spend some time discovering Scandinavia. There are a number of rail routes through spectacular mountain scenery, such as the Bergen - Oslo line and the branch to Flåm. The further north you go, the better the effects of Aurora Borealis, so maybe head for Narvik above the Arctic Circle, although be warned: the railway line up the west coast of Norway stops at Bodo, leaving you a longish ferry or bus ride. The only rail route into Narvik is via Sweden, believe it or not. InterRail zone E covers Norway, Sweden and Finland, or buy a ScanRail pass which also includes Denmark so you can take in Copenhagen.

Russia may be out, but there’s still the whole of Eastern Europe you can visit. Head for Krakow, Wroclaw, Prague and Budapest. And after that, you can head for Istanbul and the Aegean if you want to relax and soak up some sun.

Useful websites for buying rail passes are www.raileurope.co.uk and www.railchoice.co.uk. Finally, for all you need to about rail travel in every country in Europe and beyond, see www.seat61.com which is a veritable mine of information.

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