You can see the highlights of Vientiane, Laos in one long day.
A scooter will be the cheapest way if you want to see the downtown sights + Buddha park.
A bicycle will allow you to see everything in 5 hours.
Walking is a great option as well, as you can use a tuktuk at the end of the day!
Sights
A - Sisaket Temple
B - That Dam
C - Patuxay Monument
Inspired by the Arc de Triomphe
D - Pha That Luang
National icon of Laos
A must see!
F - Wat Sok Pa Luang
Daily meditations, massages, and sauna nearby!
G - Buddha Park
H - Night Market