Hey there,

https://www.mediawiki.org/wiki/Wikimedia_Hackathon_2019/Venue links to https://commons.wikimedia.org/wiki/File:MAP_INSTRUCTIONS_PDF.pdf and https://commons.wikimedia.org/wiki/File:Hotel_to_venue_directions.pdf

Both PDF files seem to contain non-free material (photos and maps) by other authors which cannot be hosted on Wikimedia Commons. Hence these files will likely get deleted soon and the links will become broken.

(Also, for future reference, the file names could be less generic as Commons has a shared namespace. There is probably more than one venue and one hotel on this planet. :P )