The harbour that locked itself shut

I like the defences you can't see in a photograph, and Dubrovnik's Old Port has a brilliant one. St John's Fortress has stood guard at the harbour mouth since the 1300s, all thick stone walls and cannon slots, but the real trick was underwater and after dark.

Every night, the people of Dubrovnik hauled a heavy iron chain across the harbour entrance, stretched from the fortress to the Kase jetty on the far side, sealing the whole port shut against pirates and enemy ships. They walled up the old Arsenal entrances too, for good measure. It's the sort of detail that never makes it into the photos, because there's nothing left to see now except calm water and fishing boats. But for centuries, this was a harbour that quite literally locked itself in for the night.

I painted it in watercolour and ink, the fortress catching the evening light. There's a poster and a postcard, both with a letter home if you'd like one.

Shop the poster here: Dubrovnik Old Port, Croatia · Travel Poster