We visited Cramond Island last week, which is a small island near Edinburgh, separated from the mainland by a causeway. When the tide goes out the island becomes accessible for 4 hours at a time before the causeway is submerged again.

The island can only be reached by foot or bike so it's a popular spot for a stroll. The causeway is about a mile long and very impressive, made from triangular concrete bollards, designed to keep speedboats out of the Firth of Forth.

The island is uninhabited but it was once a popular holiday destination. There are hidden remains of cottages and more prominently, abandoned WWII gun emplacements that frame a beautiful view of the shoreline.

We've been here a few times but never at the right time to get across. It was a triumph to make it finally, and it had the air of adventure that comes with visiting an inaccessible place. It couldn't have been a better day either - what a scorcher.

Endless photos of bollards in this Cramond Island Flickr set.