Richard Collins: Make a bee-line for Giant's Causeway — it is really impressive 

And there's a good reason why Giant's Causeway and honeycombs are hexagon shaped...

The hexagonal columns at Giant's Causeway were formed by a massive volcanic eruption. As the North American tectonic plate separated from the Eurasian plate, fissures opened through which molten magma surged to the surface. The lava cooled and solidified. The resulting columns would normally have roughly circular cross-sections. However, when cylinders are packed closely together, they leave gaps between them. The magma in Antrim continued to expand into these spaces. Only triangular square or hexagonal forms fit together snugly, in woodblock-floor fashion. The hexagon is the best compromise, and the nearest viable shape to the circle and is also used by bees when making honeycomb

‘Is not the Giant’s Causeway worth seeing’, James Boswell asked Samuel Johnson.

The great man replied that it was ‘worth seeing, yes, but not worth going to see’ — a sentiment not endorsed by Tourism Northern Ireland.