In 2015 the artist Banksy opened an installation called “Dismaland” at a disused lido in Weston-super-Mare. The faux amusement park in Somerset was a commentary on the reality of British seaside towns versus the saccharine sweetness of Disneyland, and attracted 150,000 visitors over five weeks. It was the most action that Weston had seen in living memory. Until very recently this faded seaside resort, its Victorian glory days long gone, was the almost-exclusive preserve of retirees, where they traditionally moved to live out their days. But around the country, seaside towns and beauty spots that are havens for retirees are getting a fresh injection of youth. A new ripple of Generation Z and millennial buyers, who are untethered from city centres thanks to hybrid working and in search of good value, are discovering these areas. We found the places once dominated by retirees where young people are now moving in droves. Last summer Emily Weeden, now 25, moved to Weston after spending 10 years living in Bristol. After a stint living at home with her parents near Cheddar to save up for a deposit, Weeden, who works for an energy company, spent £120,000 on a one-bedroom flat. “In Bristol you...