When the sweltering heat, humidity and heavy rains give way to the crisp air of autumn, even though it comes with a few warm and cool days, I enjoy my daily walks more than ever. The brisk air makes me move quickly and get in my 10,000 daily steps with great joy. The change of color is also welcome. I love Korea's verdant hills and mountains, thickly forested (thanks to former President Park Chung-hee's aggressive tree-planting) with all kinds of trees.