Gnome gliders are scenery which become available for use as transportation after completing The Grand Tree quest. They are able to fly players to other hubs quickly, and are useful for getting around RuneScape Classic. All of the two-way hubs return back to the top of The Grand Tree. Their examine text is "i[ ] wonder if it flys[ ]".
These locations allow travel in both directions:
This flight will crash land and the player will be unable to return to The Grand Tree: