Complex sentence: Shanghai's old airport, Hongqiao Airport, is located in Puxi however all international flights, flights to Hong Kong and Macao, and flights to most major cities have been moved to Pudong International Airport.
Split into simpler sentences: Shanghai's older airport, Hongqiao Airport, is located in Puxi. However all international flights, including flights to Hong Kong and Macao, have been moved to Pudong International Airport.