I adore bottle trees. I’ve seen broken glass used for gorgeous art work. Old bottles can be made into drinking glasses and vases with a glass cutter.
But this … this is perhaps the pretties thing I’ve seen made from empty bottles.
To make a bottle fence or wall, simply drill a hole in each bottle and run a rebar through it. Can you imagine how stunning it would be when the sun goes through it? Hopefully the reflection won’t set an ant on fire!