Heineken actually, briefly, ran an experiment where they made the bottles more rectangular, so that they could be filled with earth and then cemented together a

Heineken actually, briefly, ran an experiment where they made the bottles more rectangular, so that they could be filled with earth and then cemented together as glass bricks: https://www.smithsonianmag.com/arts-culture/when-heineken-bottles-were-square-62138490/ https://www.smithsonianmag.com/arts-culture/when-heineken-bo... Glass is a pretty good insulator and generally weather-proof, UV-resistant etc, and cheap to produce.