That's an interesting article, I like Ffion Reynold's blog very much.

As we've been walking round the Anglesey coast path this year, the unfolding geology has been amazing to see, so many different types of rock in spectacular formations. Close to Ffynnon Eilian on the north coast there is a plaque fixed to a rock outcrop that marks the place where Edward and Annie Greenly completed their geological survey of Anglesey in 1910. It took them 15 years and is an amazing achievement.