We met a teacher who uses these "bottle gardens" to teach his students about ecosystems and planetary boundaries and took time to explain the concept to us as well.
A bottle garden is a closed ecosystem which has the essential requirements of soil and water for the survival of plants that are growing inside it. Water is trapped inside the bottle and unable to evaporate. The carbon dioxide from plant respiration is used for photosynthesis, and the oxygen from photosynthesis is used for respiration.
Quite impressive how these plants grow without any human interference ... Nothing goes to waste, everything is reused. I think commercial agriculture could learn from this ... as well as every single one of us :)
It's impossible to be at Leva and not be enchanted by their garden. Pretty much exactly as impossible to say no to their sandwiches and chocolate pie!
I expanded my herb garden with some Coriander/Silantro and bought colouring pencils with FSC-label (made from wood from a sustainable source).
In other words, it's also really hard to go into the shop at Leva without buying anything :p