Not strictly in Cardiff, but just five miles off the coast, the stunning island of Flat Holm is a different world with a wealth of history and wildlife. You’ll be amazed at how much there is to discover…
Since the Dark Ages, Flat Holm has been a retreat for monks and acted as a sanctuary for Vikings, Anglo-Saxons, silver miners and smugglers. Fortified in Victorian times and again in World War II, it’s perhaps most famous for receiving the first-ever radio message across the water by Guglielmo Marconi in 1897.
A day visit by a boat provides you with three to six hours on the island, where you can purchase a self-guided tour pack or go on a free guided tour on certain dates. You can relax and soak up the island’s tranquil atmosphere and spectacular views, and also enjoy a drink at The Gull and Leek, Wales’ most southerly pub. There will also be an opportunity to visit the gift shop, where you can buy postcards, Fairtrade snacks, and a range of souvenirs as a memento of your island experience.
https://www.visitcardiff.com/highlights/flat-holm-island/