Saigon's city hall was originally a French hotel constructed between 1902 and 1908, a fantastic ornate example of refined colonial architecture. Unfortunately, it's not open to the public, but there is a small walking mall out front and running the length of the behemoth Rex Hotel, itself an important vestige of the American years when it housed the CIA headquarters. The park is a great spot for a good group photo with the majestic City Hall in the background, and the people-watching here is supreme (though you're likely to be the people that are being watched).