Enjoy your trip. I hope you have booked enough time to see the countryside and talk to people. It is the best place in the world for an American to visit to get his ego stroked. They love Americans. Not only are there no memorials, though, to American troops but the battle scars are mostly gone. Tan Son Nhat still has the old hangars but an old soldier going back won’t see anything at Khe Sanh or Pleiku or Cam Ranh that looks like there was a war there, or Americans 40 years ago. There are some old French pillboxes here and there and the Cu Chi tunnels are a major tourist attraction and the countryside is still dotted with many little round ponds. Go look at Ha Long Bay if you can. It is one of the natural wonders of the world.