Depending on how they're used, the bonuses of the Sukiennice can turn Polish cities into economic or industrial powerhouses. The Production bonuses from international trade are useful when trying to raise an army, develop a city, or build a wonder, and the Gold bonuses from domestic trade relieve some of the pressure to maintain good relationships with neighbors. Building a Commercial Hub and a Sukiennice in every city will provide the Poles with many Trade Routes, which they can then send to other civilizations while building districts, buildings, and their army. If they go to war with one or more of their neighbors, they can keep their economy strong by trading internally and with nearby city-states.
Thanks to its location between Europe and Russia, Poland’s cities were vibrant with trade, as exemplified by the cloth halls (known as sukiennice in Polish) located in the great cities of the realm. It contained trading stalls, where vendors sold cloth, leather goods, wax, salt, peppers, spices, and silk from the Far East, indeed all sorts of exports and imports. Usually built in the center of towns, these were international marketplaces, larger and more magnificent than the run-of-the-mill markets scattered about Europe. In the halls and porticos, traders from dozens of lands made deals, and the locals—those who could afford it—found all the luxuries they could desire. In Poland, the oldest and largest was the Sukiennice of Krakow, rebuilt in the Renaissance style in 1555 AD after a fire. It was an important center for international trade between West and East until the end of the 16th Century (today its stalls sell snacks and souvenirs to tourists). But the cloth hall was also vital in other Polish cities, doing a booming trade in places such as Poznan, Wroclaw, and Torun.