 If you liked
Glaucos
|
 ...then you might like
Chitei Ryokou
|
These two manga both are about adventure to the deep darkness of the earth, where humans normally wouldn't go to.
Due to this, they come across lots of beautiful and amazing natural habitats and other desolate places.
*Both of them have a person who wants to explore these wonders of nature, and another person extremely wary of its dangers.
<> Glaucos has a dark artstyle, Chitei Ryokou is rather drawn lighter.