As I've mentioned previously, inspiration for a DM should come from everywhere.
So I recently came across a couple of links that got my DM senses tingling, and I thought I'd share some with you.
Here's a link to an article about a huge cave covered in all sizes of crystals: http://news.discovery.com/earth/naica-big-pics.html
It immediately got me to start thinking:
- Maybe a frost giant lair, with the huge crystal "logs" as the building blocks for structures in the cave.
- Or a lair where the crystals are difficult terrain for the PCs, but not for the flying creatures attacking them
- How about the erratic patches and crystal logs serve as cover, or obstacle. Maybe the attackers are well trained to use the formations to their best advantage--attacking from up high and sliding down a log and engaging in melee in the next round.
- Lastly, what if the crystals are highly reflective, disorienting the PCs by providing a natural equivalent to mirror image.
And if that isn't enough inspiration, here's some other cave pictures that hopefully get you thinking... http://science.howstuffworks.com/cave-pictures.htm