(CNN) -- If there's any truth in the old saw that London's streets are paved with gold, it's probably because they've been gilded by cash stripped from the pockets of tourists.
It won't surprise anyone who's seen their budget evaporate seconds after exiting their over-priced hotel, but the English metropolis has been named the world's priciest city break destination.
Review site TripAdvisor compared prices in 48 leading tourist destinations to conclude that London has overtaken Oslo as the world capital of the inadvertent splurge.
According to the site's annual TripIndex Cities study, seven of the world's 10 most expensive destinations are in Europe.
Asia fields the majority of the list's most affordable cities for a holiday.
The list says an evening out and overnight stay in a four-star hotel in London will relieve visitors of $523 -- more than three times the cost of the same break in Hanoi, which is named as best value.
Travelers to Paris should be warned against working up too much of thirst while pounding its boulevards -- the city is identified as the priciest place for pre-dinner cocktails.
Two dry martinis there set drinkers back an average $52.
Even then the cocktails will probably be watered down by the salty tears of whoever's footing the bill.
New York still the place for expensive hotels
TripAdvisor's research reveals Stockholm is the costliest place for an evening meal.
For the same money in Hanoi visitors can can pay for a four-star hotel, cab fare, cocktails, dinner for two and still have enough change to call Sweden and gloat.
New York tops the list for expensive hotels for the second year running, with a night in a four-star hotel costing an average of $365 -- four times the price of the same deal in Bangkok.
While Oslo may have lost out to London in the overall list, the Norwegian city still rules when it comes to taxi fares.
There, a three-kilometer (1.9 mile) journey will set customers back $57.
In Jakarta, the cheapest city, the same journey can be made for less than $3.
Here's TripAdvisor's top 10 of most expensive cities: London, Paris, New York, Stockholm, Oslo, Zurich, Copenhagen, Helsinki, Toronto, Sydney.
Here are the site's best value destinations: Hanoi, Jakarta, Sharm el Sheikh, Bangkok, Sofia, Cape Town, Mumbai, Kuala Lumpur, Prague, Budapest.