There is a good conversation going on on the BBC News site about whether Auschwitz should be preserved or left to rot. My vote, preserve it. In fact expand the presentation with film libraries constantly playing of the camp, the ovens, the deaths, and most importantly the overall count of how many died in all the camps.
If we (or rather Poland in Auschwitz’ case) let it rot it fades from memory, and we humans have a very nasty habit of repeating history and not learning from it (the religious wars of the 16th century – the current Islamic insurgencies).
Germans are not Nazis as they were, they are repelled by what happened (at least we assume so and are shown so), so it is in their interest just as much to preserve such places. The Nazi party rose on the back of a terrible recession with a strong leader promising to bring Germany back to power and prestige. If we let such camps fade we are in danger of that happening again somewhere.
Lastly, we -should- be reminded of such places, the very depths that humanity can sink to. And don’t for a minute think that Germans are the only ones capable, the Russians did the same and worse, the North Koreans are accused of similar. If they can do it, so can we, so we should teach our children what should not be done, and camps like Auschwitz are clear examples.