Kuala Lumpur was ranked the 6th most-visited city in the world on the Mastercard Destination Cities Index in 2019. Since the 1990s, the city has played host to many international sporting, political and cultural events, including the 1997 FIFA World Youth Championships, 1998 Commonwealth Games, 2001 Southeast Asian Games, and 2017 Southeast Asian Games. Kuala Lumpur has undergone rapid development in recent decades and is home to the tallest twin buildings in the world, the Petronas Towers which have since become an iconic symbol of Malaysian development. Kuala Lumpur is well connected with neighboring urban metro regions such as Greater Kuala Lumpur and Klang Valley via the rapidly expanding Klang Valley Integrated Transit System.