The twins knew that Etherian couldn't talk about it openly. However, the fact he knew about something like that, and it still existed to be used, meant that the Sacred Land also kept an eye closed. The Sacred Land, or probably its elders, most likely had their hands in some sort of profit from the smugglers. Perhaps even Etherian himself was one of them.
Etherian continued after the twins made their decision. 'Unlike the Sacred Land's official openings with other countries, the cultivator smugglers transfer people to other continents every five years. In the Sacred Land's case, we do that once every ten. Just like here, the smugglers on the other side also have connections to prevent the controlling power of those continents from intervening.'
'However, the most I can do is show you where you can find them. Also, it won't be cheap.'