Mystaran Campaign: Impact Craters and Impact Caverns

 

It's because the impact of the meteor in southern Glantri that we now need to consider the prospect of a deep cavern having formed far below the great crater. For now it will be uninhabitable, but the idea that far in Mystara's future that cavern will become home to life different to life on the surface means that Adventure is to be had.

Likewise, there should be a cavern below Meteor Crater in Arizona. And if it is found to contain an ecosystem, that opens the possibility for life or even water to be found deep beneath craters on the Moon and even Mars.

Aliens!