Round table

And you can just dump all the junk there, lol, I'm such a noob :D, I've never used it, what about external markets?

On external markets, you can only buy artifacts. In castles, building it costs 10,000 and it doesn't always pay off. Also, the price of artifacts is influenced by the number of markets in the castles you own; the more you have, the better the exchange rate (you sell more expensively and buy more cheaply, the situation is the same as with resource trading). Also (for those who don't know), the artifacts in castles are the same for all players (human or computer) for a month. When you buy an artifact in a castle, it is removed from the market for all players. On the first day of each month, all artifacts are updated (one of the advantages of being a red player is buying them first).