Inspired by a sink full of soap bubbles: how we made the Eden Project

As the spectacular Cornish bio-domes turn 20, their creators reveal how they were inspired by a lost civilisation - and a load of washing up

I had successfully turned a long-disused garden in Cornwall into the Lost Gardens of Heligan and was looking for another big project. I started thinking about an epic setting to showcase the world's most important plants. Horticulture didn't seem to be taken seriously, and I wanted to make people think differently about our environment and relationship with plant life.