What are these strange rocks?

CrowdScience listener Liana from Canada got in touch to ask about some very specific rocks she’d seen on an island in Indonesia – jagged, rugged and a very strange shape: hexagonal. They were in long columns, and clicked together like a jigsaw. But what are they, and how did they get there?

Across the world in the UK, CrowdScience listener Sarah emailed us to ask about the famous rocks of the Giant’s Causeway in Northern Ireland. What makes them so uniformly hexagonal?

Presenter Alex Lathbridge investigates, visiting the Giant’s Causeway to speak to geologist Dr Kirstin Lemon from the Geological Survey of Northern Ireland. She explains how this amazing landscape formed, and why the mythical rocks look the way they do today.

We also hear from Dr Alfend Rudyawan from Institut Teknologi Bandung in Indonesia about Liana’s intriguing rocks. Are these distant locations more closely related than you might think?

And we look to nature – because angular, uniform hexagons crop up surprisingly often. Professor Jean-Marc Schlenker from the University of Luxembourg explains why hexagons are much better than other shapes.

Presenter: Alex Lathbridge

Producer: Hannah Fisher

Editor: Ben Motley

(photo: Giant`s Causeway in Northern Ireland Stock photo- Credit: MANUEL FIL ORDIERES GARCIA via Getty Images)