The world's largest cave is sold out for years ahead, and scammers have noticed. Oxalis Adventure, the only operator licensed to run expeditions into Sơn Đoòng Cave in Việt Nam's Quảng Trị province, has gone public with a warning that several fraudulent websites are posing as its official booking platform and taking money from would-be cave explorers.
The company's general director, Nguyễn Châu Á, flagged the issue on October 7. The fake sites are convincing: they mirror Oxalis's interface, images and copy almost entirely, and the people behind them have used AI tools to generate and polish materials. Domains identified so far include oxadventur.com, oxadventura.com and oxadventure.shop — close enough to the real thing to fool anyone booking in a hurry. Worse, the scammers buy Google Ads so their listings appear prominently when people search for Sơn Đoòng tours.
Some travellers have already spotted the red flags. In several cases, customers noticed something off during the booking process and double-checked before paying, so no money changed hands. Oxalis is now reporting the matter to the Quảng Trị provincial Department of Culture, Sports and Tourism and to police.
There's one easy way to tell a fake from the real thing: the genuine Oxalis process never asks for payment at sign-up. A consultant contacts each applicant to confirm details, offer guidance and assess fitness levels, and you only pay once you've been cleared to join an expedition. If a site wants your money up front, walk away. The company also advises travellers to scrutinise domain names, check operator details, be sceptical of results reached through paid ads, and never transfer money until the booking is verified.
The warning matters because Sơn Đoòng isn't something you can rebook elsewhere. Access is strictly controlled, groups are capped at 10 people, and expeditions run six days and five nights for participants aged 18 to 70. The current price is US$3,000 per person, and the season runs from January to August each year. Demand is so strong that Oxalis says trips are fully booked through 2028 — which is exactly why a too-good-to-be-true offer, or an apparently available slot, should set alarm bells ringing.
If you're dreaming of Sơn Đoòng, book directly through the operator's verified site, check the URL character by character, and confirm any payment instructions by speaking with the company before sending a cent. And if the wait list is too long, Việt Nam has other spectacular caves in the same Phong Nha–Kẻ Bàng region that Oxalis runs trips to, with shorter lead times and lower prices.
