I was five when I first saw the folly, a ruined stone tower in the parkland by my childhood home. I was out walking with my dad shortly after we had arrived in town. We were striding through the long grass, he with a thermos and newspaper under one arm, and me with a wooden sword and shield. I struggled to keep up. "What's a folly?" I asked. I'd never heard the word before. "It's a bit like a toy for rich lords and ladies," said my dad, "they built them to make their gardens look more excitin..