/skins folderThis folder holds the skins for the blogs.
b2evolution Note: this folder only pertains to the public interface skins. The skins for the admin interface are to be found the the /skins_adm folder. 
Each available skin can be found in its own subfolder. You can install/create additional skins by copying/creating new subfolders into the /skins folder.
Subfolders starting with a _ represent available skins which will remain hidden to the users. Those are typically used for RSS skins.
Fallback templates can be found in folders like /skins_fallback_v5, /skins_fallback_v6, etc.
This folder needs to be accessed through the web.