Photo taken on Sept. 23, 2018 shows the murals and graffiti on the walls in Greater Northside Houston area, the United States. Over a hundred world artists gathered in Houston, the fourth largest city of the United States, from Friday to Sunday, presenting all kinds of street art paintings on the walls of various buildings. Coming back for the sixth year in a row, the street art festival, Meeting of Styles, is bringing world-class artists to the Greater Northside Houston area. (Xinhua/Yi-Chin Lee)