Porthmadog
It's from Porthmadog that Prince Madog sailed to North America in 1170*. He didn't discover America, it had been discovered many years before his arrival by the native Americans who were already living there. Madog supposedly traded with the Mandan tribe and some of his crew joined the Mandan*. Legends persisted for years about a "Welsh tribe" with the Mandan having some words of Welsh in their vocabulary. In 1796 the Welsh explorer John Evans spent a winter with the Mandan in order to study their language and discovered they didn't speak any Welsh.
A miniature railway runs from Porthmadog to Blaenau Ffestiniog, no one knows why it was built but local legend states that, at one time, it transported umbrellas and raincoats to Blaenau where it rains 364 days a year.
*This is probably total bollocks...