The Tate Modern has housed some strange art—huge curving slides, a massive artificial sun, and a giant spider, to name a few. But its new installation is the strangest yet: a mind-boggling carpet of 100 million sunflower seeds.

The seeds, installed by Chinese conceptual artist Ai Weiwei, come as the eleventh commission in the Tate Modern’s Unilever series, which fills the museum’s central Turbine Hall with big, unusual and often interactive art. Weiwei’s seeds—all 100 million of them—are not actual sunflower seeds but porcelain replicas, hand-crafted and individually painted over the course of two years by some 1600 Chinese artisans.

This is what you get when you have 1601 people with too much time on their hands.