Dartmoor in Southwest England typical highland sight
One of the things that surprised me, and many other first visitors to the British Isles, is the moors that form at higher elevations throughout the country. For we often think of England as pleasant forest and pasturelands. Whence come these grim often rainy and foggy countrysides? Well, you must remember that the UK, for all its mild climate, is well north of the United States on the average, being located at the same latitude as Labrador in North America! Hence the winter nights are long and cold, especially at the higher elevations. Thus the climate is nowhere near as charming at these points as it is further below; little can grow and thrive in the harsh weather, usually only tenacious grasses and low gorse or shrubs. You are looking at the equivalent of the treeless zones of northern Canada: the Gulf Stream can spare them the cruel winters of that northern land, but it cannot make up for the lack of light.
The moors are at their best in the fog and misty rain, when with a bit of imagination one can quickly become convinced that the hound of the baskervilles will soon attack you. From time to time, when the fogs close in, you can ride for hours with visibility in the single meters. One time a shape did, spookily, arise massively in front of me: it was a radio transmission tower; but could just as easily have been an ogre out to grind me into the stones of the aged country. Also, from time to time, the remains of ancient Roman stone roads cross and vanish over the misty hillsides.