The market "Fairground" to the West sees a lot of growth in the warmest months, and tends to shrink back down as the seasons cool off.
There are permanent structures that house many of the shops, but in the busiest months the Market expands into a tent city. Space is at a premium, and since the forest is not cleared out to make more space, a good deal of vendors end up selling their merchandise under (and sometimes in) the trees. The Market extends only to the East, as villages and another hard barrier to the West prevent it from expanding in other directions.
There are booths with different vendors selling their wares, from fruit to weapons, bizarre human "treasures" and delights from both the Demon and Fairy realms. Not always the best deals are to be had, but if you are seeking a rarity you'll probably find it here, though you may want to keep your own valuables close to you while you're there. Not every shopper is friendly and not every vendor wants money for your exchange.
The Demon Market is Samrick's most important center of commerce. Because all folk from the different nations are welcome to set up shop, many Kingdoms try to get a foothold to circulate their currency through the market. Sometimes, special deals are offered to those who use the currency a vendor wants to receive. For example, a Fairy vendor wants to empower the Fairy Kingdom, so they will offer a discount if the buyer pays in Fairy coin, even if the Elf coin is at higher value.