Thailand’s Wat Pa Maha Chedi Kaew has a unique distinction among Buddhist temples: It’s made of beer bottles. When the building was begun in the 1980s, the monks were seeking ways to encourage waste disposal and promote environmentalism. They had been collecting beer bottles since 1984 and decided to use them as a building material.

The main temple, completed in 1986, comprises about 1.5 million bottles. The monks say they provide good lighting, are easy to clean, and retain their color — the green bottles are Heineken and the brown ones are the Thai beer Chang. They even use the bottle caps to make mosaics of the Buddha.

The monks have gone on to build a complex of 20 buildings, everything from a water tower to a crematorium, from the same material. Abbot San Kataboonyo told the Telegraph: “The more bottles we get, the more buildings we make.”