In England’s Lake District, nature rules and humanity keeps a wide-eyed but low profile. At just about 30 miles long and 30 miles wide, the region is a lush, green playground for hikers and poets alike. William Wordsworth’s poems still shiver in its trees and ripple on its ponds. There’s a walking-stick charm about the way nature and culture mix here. Walking along a windblown ridge or climbing over a rock fence to look into the eyes of a ragamuffin sheep, even tenderfeet get a chance to feel outdoorsy. I’ve come here to enjoy some natural thrills and renew my poetic license. I focus on the northern lake of Derwentwater, with the nearby town of Keswick as my home base. It was an important mining center through the Middle Ages, but slate, copper, and lead gave way to Romantic poets and tree-hugging tourists in the 19th century. Keswick’s fine Victorian …