The surreal building features a 12-storey tower, ornate golden domes and a grass roof planted with lime, beech and maple trees. Its colourful facade is said to reflect the soil layers found in the earth beneath the building, while trees – known as 'tree tenants' – grow out of some windows.

Hundertwasser is known to have disliked order, even declaring: "The straight line leads to the downfall of humanity." Instead, he embraced non-conformity, going so far as to ensure not one of the more than 1,000 windows in the building was the same.

Germany’s weirdest buildings from a UFO home to Castle Frankenstein