A few days ago, I put together a number of icons in the style of the classic D&D Expert blue rulebook (and others). I had not seen something similar.

Linked is a sample map key showing the icons and a zip with individual 300x300 transparent pngs, and you're free to use them for any purpose, as far as I'm concerned.

I did them for my project Hexographer which helps people create hex maps quickly and easily. To use these in Hexographer you need to use the pro version which allows a user to switch the icons from the defaults. But as I said, anyone can use these, even if you want to turn them into brushes for Photoshop/GIMP or whatever.

BTW, the one icon I'm unhappy with is the sand dunes icon. If you have an alternate idea for it, please describe it or post it (if I can include it in the zip.)