Take a day trip to the Cu Chi Tunnels, an underground network used by the Viet Cong during the Vietnam War. You can crawl through the tunnels and learn about the guerrilla tactics used by the Viet Cong. In the afternoon, head to the Mekong Delta, where you can take a boat ride along the river and visit local villages. You can also try some of the local fruits and dishes, such as coconut candy and elephant ear fish.