Keith Green has an unusual interest in empty, unused properties, even while he is on vacation. Recently, Green, an American, was visiting Shanghai, China. He went out for dinner when he discovered something that made him stop and take a picture. “Everyone else is taking pictures of the skyline,” he told VOA. “I’m taking a picture of a vacant lot.” Most travelers do not seek out vacant properties. In Green’s hometown of Philadelphia, Pennsylvania, vacant lots are often home to increased crime. People often leave trash or hide illegal weapons and drugs in them. But Green is leading an effort to remove these problem areas from Philadelphia’s low-income communities. In their place, he creates “green spaces,” or areas that are like small parks, with plenty of trees or other plants. It is a huge job. The city has an estimated 40,000 vacant lots. Still, Green is seeing how a little green space can make a big difference in parts of the city that experience high levels of poverty and crime.