Cycle parking has always been a problem in the Netherlands. There are so many bikes, and they take up a lot of space and a lot of innovative ways have been though of to deal with the bikes.
One of the first, and perhaps the most famous, of the huge cycle parks is that in the photo above - the Fietsflat at Amsterdam Centraal Station. This dates from 2001 and can accommodate 2500 bikes on three levels.
It's no longer anywhere near the biggest. I have previously posted about Groningen's new railway station parking which accommodates 4150 bikes, bringing the total there to well over 6000 (since this was written it's been expanded and you now find 10000 bikes at the station). I have now heard that Utrecht is building spaces for no fewer than 20000 bikes at a new cycle park at the central station. Even Assen with its population of just 65000 will soon have 2300 spaces - nearly as many as in the fietsflat (this has also been increased to over 2500).
The railway company here doesn't really want to upset cyclists, as four out of every ten train passengers arrive at the railway station by bike. However, they have started talking about the idea of charging for cycle parking at railway stations because the cost of providing it is so high. This is compounded by the problem of people dumping old bikes at the station. Another possible approach they could take would be to pay people to look after guarded parking at the station. It would make it easy to tell what bikes had been abandoned.
The problems of having so many bikes go back a long way as you can see in this film from 1958 (courtesy of BeeldenGeluid):
The video says (roughly translated) that:
"There are 900000 people in Amsterdam and 600000 bikes, and that this causes problems in the rush hour. What's more, cyclists have the same problems as drivers in finding places to park their bikes. You'll see a guarded double decker cycle park which dates from that time. They keep your bike safe, and you can book spaces in advance in order to make sure you will be able to park your bike regularly.
Then there is the problem of bikes parked where they shouldn't be on the street, which get in the way and can look unsightly. Some are dumped or stolen. The police collected 2500 bikes off the street at this time, and reduced the rate of cycle theft. A hundred bikes were returned to owners who knew their frame numbers, 150 more were identified by their owners visiting the "bicycle graveyard" to find their bikes and the rest were auctioned."
There are more cycle parking stories.
The photo at the top comes from wikipedia. More details, and licensing conditions for the photo can be found here. In Dutch, "flat" refers to an apartment block, while in English, "flat" refers to a single apartment. Hence the reason for the name "fietsflat" - bicycle apartment block.