Mrs Sunshine and Mr Moon will give you the tour of Vienna Prater; they're about the only people around at this time of year, especially when temperatures are below freezing.
There are two big Ferris wheels in Prater and this one actually's not the famous one, it's just the Blümerlrad (flower wheel):
It's much cheaper and you don't have to wait for hours till it's your turn; on this day however the Blümerlrad was standing still while the famous Riesenrad did turn around (and there were no queues at all, those prepared to pay the fee got a ride without having to wait):
Roller-coasters there are plenty, this is but one of the many which weren't open:
And here's the Children's Land where also all doors were closed.
