The Waterdeep: City of Splendor book has maps of the city all divided up into districts so I took them all and photoshopped it together. Some of the scaling doesn’t match up so I tried cutting it up and moving it around a bit, and it looks pretty good. 

The image here is gonna be compressed, but I have an uncompressed version on my Google Drive that’s perfect for printing; got mine printed out on A0 paper and all the labels are still legible B-)