If you have any 500 Euro notes hanging around it may be an idea to

get them to the bank. Apparently they are almost the exclusive preserve of the money laundering business. The banks had recently secretly agreed to withdraw them from circulation before going public on the matter. One million pounds worth of 500 Euro notes weighs about the same as two bags of sugar! making them very easy to smuggle around Europe.

No storage requirements there then, thank goodness !