Don't miss a visit to Ho Chi Minh's tomb. You must be dressed properly to enter. Ladies, your shoulders must be covered. If they aren't the staff will insist you buy an overpriced Vietnam t-shirt at the gate, as I had to. You are then shepherded in to a line in pairs and led for quite some distance to get to the building where Uncle Ho is. You are led through the tomb and musn't stop or chatter on the way or the guards will move you along.
It is amazing that so many Vietnamese of all ages still line up to visit and pay their respects.