Ynys Llanddwyn is a tiny tidal island which, at low tide, is attached to the Isle of Anglesey in Wales. Ynys means 'island' in Welsh and Llanddwyn means 'the church of Dwynwen,' the country's patron saint of lovers.

Legend has it that Dwynwen, a 5th-century Welsh princess, sought solace on this island after a tragic love story. The young woman fell in love with a commoner, but because her royal father forbade the union—and briefly turned her beloved into a block of ice—she moved to the island and set up a convent. She dedicated her life to spirituality, living as a hermit and helping others with matters of the heart. The ruins of Dwynwen's church, a well, and a convent remain on Ynys Llanddwyn and St. Dwynwen's Day, on January 25, is the most romantic day in Wales—the country's very own Valentine's Day.