By Rick Steves
Things happen: You run out of money, you get into town too late to find a room, or volcanic ash strands you somewhere without a place to stay. I once went 29 out of 30 nights without paying for a bed. It's not difficult…but it's not always comfortable, convenient, clean, safe — or legal.
I no longer lug a sleeping bag around, but if you'll be vagabonding a lot, bring a light bag — you'll find plenty of places to roll it out. Just keep your passport with you, attach your belongings to you so they don't get stolen, and use good judgment in your choice of a free bed. Faking it until the sun returns can become, at least in the long run, a good memory.
The Great Outdoors
Some large cities, such as Amsterdam and Athens, are flooded with tourists during peak season — and some of those tourists spend their nights dangerously in city parks. Most cities enforce their "no sleeping in parks" laws only selectively. Away from the cities, in forests or on beaches, you can pretty much sleep where you like. In my vagabonding days, I found summer nights in the Mediterranean part of Europe mild enough that I was comfortable with just my jeans, sweater, and hostel sheet.
Assuming you can find one that stays open all night, a train station can be a free, warm, safe, and uncomfortable place to hang your hat. Most popular tourist cities in Europe have stations whose concrete floors are painted nightly with a long rainbow of sleepy vagabonds. Some stations close for a few hours in the middle of the night, and everyone is always cleared out at dawn before the normal rush of travelers converges on the station. Any ticket or train pass entitles you to a free night in a station's waiting room: You're simply waiting for your early train. For safety, lock your pack in a station locker or check it at the baggage counter.
Your success at actually getting shut-eye on a train hinges on getting enough room to stretch out, and that can be quite a trick. It's tempting but risky to sleep in a train car that seems to be parked for the night in a station. No awakening is ruder than having your bedroom jolt into motion and roll toward God-knows-where. If you do find a parked train car to sleep in, check to see when it's scheduled to leave. Some rail-pass holders get a free, if disjointed, night's sleep by riding a train out for four hours and catching a different train back for another four hours.
After a late landing, crash on an airport sofa rather than waste sleeping time looking for a place that will sell you a bed for the remainder of the night (for a guide to airport slumber, try The Guide to Sleeping in Airports). Frankfurt's airport is served conveniently by the train and is great for sleeping free — even if you aren't flying anywhere.
Tents and Dorms
Big, crowded cities such as London, Paris, Munich, Venice, and Copenhagen run safe, legal, and nearly free sleep-ins (in tents or huge dorms) during peak season.