Going on holiday shouldn't mean leaving the dog at home, and thankfully, as a nation of dog lovers, Britain has plenty of places where you can bring your pup along. Whether you're after a swish city break or an adventure in the mountains, or perhaps a coastal escape to the seaside, there's a destination for every dog across England, Scotland and Wales. Here, Lottie Gross – author of Dog-Friendly Weekends – chooses her favourite.