In Lost Ark, you will come across different islands to practice your different Trade Skills called Platinum Fields. You can enter these instances either by yourself or with a group of up to four people so long as each of you has an Entrance Ticket: Platinum Field (Bound) to use before entering.
Since the main purpose of Platinum Fields is to help develop your Trade Skills, you can do so all you want without losing any of your energy (the green bar above the Trade Skills menu). It’s also important to note that you only have 15 minutes to train in what you can before it ends once you start.
As of right now, there are only two different kinds of Platinum Fields for different types of skills: Nahun’s Domain and Old Yudian Canal. Nahun’s Domain is for Foraging, Logging, and Minin, while Old Yudian Canal is for Fishing, Hunting, and Excavating.
Since a maximum of four items can be brought back by each player, it’s better to try to head in with as many players as possible.
For more Lost Ark, check out All monster locations in Arthetine in Lost Ark on Pro Game Guides.
