Sleeper trains have the advantage of cutting out the number of daylight hours you waste travelling from place to place. Given you're getting a reasonable night's sleep for a seven or eight hour train journey, you're basically multi-tasking. The disadvantage is that you tend to get to a place feeling pretty filthy and you can't actually check in for a good few hours.
Thankfully the people at our hostel in Krakow let us dump our bags and use the showers even though we couldn't check in for another six hours. We cleaned ourselves up, and headed back to the main train station to catch a bus to Auschwitz.
Without making it sound too much like the whole inter-railing trip was some sort of grim Nazi pilgrimage, Auschwitz was probably one of the focal points of the trip. Quite a few of the cities we were visiting were open to being cut (or added, as was the case for Munich), but Krakow was a fairly permanent fixture because the intent was always to go to Auschwitz.
The place itself is about an hour and a half by bus from Krakow, and while entry is free, we got a guided tour (entry to the Auschwitz I camp during tourist periods is by tour only anyway).
To be honest, there's not a huge amount to write here. Probably the best indicator for the place was the fact that the tour was very understated. There was no dramatization, no overly sensational stuff - there didn't need to be. It's harrowing enough just being shown round the exhibits (the masses of belongings of camp victims, and in particular the mass of stored human hair were particularly unsettling), the pictures, the various sections of the camp.
From Auschwitz I there's a bus and continuation of the tour at Auschwitz II, the much larger section of the camp. Again, a fairly plain description of the living conditions is all that's really required for the horrors of the place to seep through. It's completely staggering at the personalities an ethics of the people involved who could impose such conditions, and how a place like that could have seen the clinical extermination of over a million people in the space of two years.
In total the Auschwitz trip took up pretty much the entire day, and by the time we got back it was early evening. We checked in, went out to eat and ended up back at the hostel.
For the second day in Krakow, the other guys wandered around the city, and I headed out early to go to the Wieliczka Salt Mines. I'd never heard of them before, and they only had a fairly fleeting mention in the guide books, but I'd been relayed information by my Dad that they were apparently awesome, and they seemed interesting enough from the leaflet.
The first faff was getting there, which is a straightforward journey by train, but I wasn't sure if my inter-rail pass was valid for the train operator. The language barrier proved particularly difficult, as everyone I spoke to seemed to have no idea of what I was actually trying to ask, and the most information I ever seemed to be able to get was the platform my train left from, which I was already well aware of. I got on the train anyway and it turns out that my pass was valid, or at least the ticket inspector seemed to be OK with it. As an aside, there were a few things online saying that getting the train to the mines was a bad idea. I don't know how much the ticket would have cost if I'd had to pay, but the mines are like a five minute walk from the train station in Wieliczka, so I'd recommend the train to anyone with an inter-rail pass.
The mines themselves were pretty spectacular. One of the first World Heritage Sites, they are the oldest salt mines in the world, and they contain around 300km of tunnels (obviously you don't see all of them). The tour guide was really good, spoke extremely good English, and had a pretty good sense of humour. The rock salt the mines are built through is apparently the only rock salt in the world that is edible without purification, as it has such a high purity, and you can taste the walls and ceilings without worry of being ill (it would seem somewhat unhygenic given the number of other people who will have done so beforehand, but the high salt content kills bacteria).
There are various carvings in the salt, and some spectacular caverns. Taking photos in the mines needs a fee of another 10 Zlotti, and given my dwindling amount of Polish money and limited camera battery I didn't bother, though I did sneak a couple in one of the more spectacular caverns.
There are numerous carvings in the wall (one is a copy of Da Vinci's 'Last Supper') and the chandeliers are made from recrystallised salt. It's some cool stuff.
The trains from Wieliczka to Krakow run every hour, and I managed to miss one by about three minutes, so I wandered around the town a bit. Wieliczka is a pretty small town, and it feels properly Eastern European wandering round. The train station is basically just a strip of raised asphalt next to some heavily weed-covered tracks, but walking around the town itself was fairly nice and it killed the time pretty well.
I got to Krakow late afternoon and met up with the guys, who had spent the morning seeing the city and going to the castle (which they didn't particularly rave about). We did a bit more wandering, mostly because I hadn't really seen much of the city at this point, and then, pretty knackered, we sat in the food court of the huge shopping centre next to the train station for a couple of hours until our train to Prague was due.
Overall Krakow was very different to the other places we've been to, in the fact that I barely spent any time in the city itself and just used it as a base between other places. That said, it didn't feel like there actually was much else left to see in the city itself, so I'm not sure whether an extra day would have actually been a huge amount of use. Auschwitz and the Salt Mines were definitely worth the excursions though.