Bangkok

The river, one temple, and the rest of your meals on the street.

Good to know

Go: Use the boat on the river instead of sitting in a taxi.
Skip: Skip a second grand temple. Wat Pho or the palace, not both on the same morning.
Eat: Eat on Yaowarat after dark. Point at what is on the grill.
Entry: Thailand has a visa exemption for many passports. Confirm the number of days you are allowed before you fly.
Timing: April and May are the hottest months to be outside. December, January are easier.

River boat
$2
Old City · morning
The public boat is the useful one. A dinner cruise is a different budget.
Grand Palace
$15
Old City · morning
Go at opening, in clothes that cover knees and shoulders.
Street breakfast
$4
Old City · morning
Jok or a rice soup from a cart with a queue.
Chatuchak
Free
Chatuchak · morning
Weekends only. Go when it opens, before the heat.
Yaowarat at night
$8
Chinatown · evening
Point at the grill. Sit only if there is a free plastic stool.
A daytime massage
$18
Sukhumvit · afternoon
Pick a shop you can see into from the street.
Lumpini Park
Free
Sukhumvit · morning
Good for an hour. The outdoor gym is the local part.
A rooftop drink
$24
Sukhumvit · evening
One drink. The view does not improve with the second.

A typical cost in US dollars, so you can decide before you open a booking site. Not a live fare.