70s/80s European child movie

[jock]

It was about a group of children that were trying to combat a witch. They went to something like a dream world through some big pipes, that were in the city park or something. It looked like a Russion or Polish movie. Thanks in advance.

[akiratubo]

Could be City of Lost Children.

http://www.imdb.com/title/tt0112682/

Not about a witch, but there are a couple of characters who could be mistaken for a witch if you don't remember the movie completely.  There are also pipes, lots and lots of pipes.

[jock]

Sorry, but it's not that! The one I remember was from the 70s/early 80s and it was not as dark as this one. It was from a Slavic country, I guess. It may be Arabella, but I don't remember any pipes in Arabella.

[jock]

It's Arabela, not Arabella btw. My mistake.