Evening street food crawl: try bun thang, bánh cuốn and sit at a bia hơi corner for fresh local beer; night market runs on several streets from ~6:00pm–11:00pm.
Enjoy fresh central-Vietnam cuisine at a riverside restaurant in Hoi An’s old town; many places serve until late and the lantern-lit town is atmospheric.
Walk between the iconic Reunification Palace (visitable 8:00am–4:00pm) and the nearby Notre-Dame Basilica and Central Post Office for classic Saigon architecture.
Full- or half-day boat tour to villages, floating markets (seasonal), fruit orchards and local workshops; tours usually start early (7:00am–8:00am) and return mid/late afternoon.
Back in the city by mid/late afternoon — stop at Ben Thanh Market for last-minute shopping and souvenirs; market hours typically early morning to ~6:00pm.