Why is the airport tax at some airport charged outside the airfare ticket but instead must be paid at the airport? Example from Uyuni airport
houston
liege
afghanistan
yemen
chicago
discover-card
sea
oneworld
bergamo
british
venice
sas
ecuador
weather-and-climate
viking-line
somaliland
vancouver
mct
hyderabad
maastricht
hostelworld
airports
detroit
star-gazing
manila
eu-citizens
lock-screens
nte
visa-sponsors
russia