If you don't have a lot of time in Sai Gon, so why don't you go to Cu Chi tunnels and Mekong Delta together? This is the best itinerary to explore 2 famous places in the South of Vietnam. The Best Combination Tour depart from Saigon: Mekong River and Cu Chi Tunnels in 1 day only. Then come back to your hotel around 5:30 - 6:00 Pm.