So I'm taking a new group of novice players through B2, The Keep on the Borderlands, a.k.a. The Caves of Chaos. This is my 4th time through, once as player, 3 times as DM. When I first started, we used pencil marks on graph paper. Then we quickly progressed to a dry-erase battle mat, basically a sheet of graph paper under an 11x14 glass picture frame. Over the years with a new group of players we eventually progressed to a rolled 24x36 battle may. And with my current group of kids to whom I'm teaching the game, we finally have a digital battle mat (an old 47" flat screen TV that was having reception issues and got re-purposed by being mounted in a frame to lay horizontal).

For this game, I found a realistic battle map from Jon Pintar on the Dungeon Master's Guild web site. I use it in MapTools to project it from my laptop onto the TV screen. And it has worked out fairly well.
Room 38.JPG
gdwqfbh.jpg

But my players are going to eventually need to explore the Cave of the Unknown section that is not fleshed out in the original B2 module and was left up to the DM to create. I never did like my version I created ages ago, so went in search of a better one. I found many of them out there on the web, but I was particularly fond of this one: Cave of the Unknown map by Druvas.
You can find the original posting here: Druvas' Maps (made with GIMP) on Dragon's Foot
Cave of the Unknown by Druvas.png
And here it is fleshed out: Druvas' Maps (made with GIMP) Description

But the battlemap was in the old school format white on blue, not quite the same format as the one available from the Dungeon Masters Guild. So I went to work.
I'm not that sharp with Photoshop, but I use Powerpoint all the time for my work. So basically I imported the Druvas map into Powerpoint, set white as transparent, copied sections from the Pintar map, and pasted them in. At first they were set on top for positioning, then brought the Druvas map to the foreground, and then I went back to touch up spots that didn't quite match up so well.
I made a few modifications (extended some corridors, enlarged some rooms, added some textures from photos), but it mostly matches the same layout as the Druvas map and the same style (since it was cut and paste) from the Pintar map. Note that due to the screen capture limitations and Powerpoint save-as limitations, it is low resolution when compared with the excellent quality of Pintar's realistic maps.
Given the current situation, it will be a while before I have a chance to use it with my players. But after all that work, it would be a shame for it to go to waste. So if you have a use for it, please go ahead and grab it.

Upper Level
Cave of the Unknown Upper V1.jpg

Lower River Level
Cave of the Unknown River V1.jpg

I left off any doors and a lot of other details, such as the tree in the water pool room, the rope bridge across the river, and the statues found throughout the temple complex, so they can be added later in your favorite game map program (MapTools, Roll20, or whatever).

Please enjoy.