A world hidden 30m below Budapest
bbc.com
bbc.com
Is there something I'm missing here or is the BBC just messing with us all?
Here's another video: https://www.youtube.com/watch?v=jV5LlnMDxOc
And many more from google images:
https://www.google.hu/search?q=kőbánya+barlang+búvár&source=...
As for other underground passages, Budapest has several caves too [2][3][4], and a set of passageways that connect the famous Gellert Baths with its historic source deep in the mountain [5] and now contain mechanical rooms and other boreholes for the Baths' thermal water that are further from the Danube, so they don't mix in times of high water.
[1] http://iho.hu/hir/amikor-dizelmozdony-jar-a-metroalagutban-1... [2] http://www.dunaipoly.hu/hu/helyek/bemutatohelyek/pal-volgyi-... [3] http://www.dunaipoly.hu/hu/helyek/bemutatohelyek/szemlo-hegy... [4] https://en.wikipedia.org/wiki/Gell%C3%A9rt_Hill_Cave [5] https://www.nlcafe.hu/foto/20150410/alagut-gellert-hegy-alat...