You can always generate your own with the command "nav_generate"

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1929791420

or try the TF2 slender gamemode maps; if you don't have a navmesh for those, i got'cha

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1910960381

oh and btw, the nav_generate command doesn't work for all maps, thats why i exist

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1931172582

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1931425604

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1932077942

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1932079816

To be completely honest, there's no need for good maps, as Niko said, the limit of Slender maps is the amount of maps (with a generate-able nav mesh) on the workshop, so it's pretty much Endless. You can make any map (with a Nav mesh ofc) and make it look Slender like.

I recommend using the Navmesh tool editor, so if you do wanna add props to make slender go around, you can delete that area of Nav.

I highly recommended Stop It Slender or Slender Fortress maps, they fit for this addon.

@=[o.W.n]=KuromeThe76Soldier
@Evan

You can auto generate nav meshes for maps that says "no valid walkable seeds" if you use the sanic nextbot addon to auto generate a mesh. I dont know exactly how the sanic goes around it. (Maybe it spawns a starting point beneath himself during spawn?) but it works!

nav_mark_walkable and nav_generate also do the trick, just enter nav_mark_walkable at the position where you want it to start generating

@=[o.W.n]=KuromeThe76Soldier i tried that before but it didn't work. But could be that i just managed to screw up something lol