Junction

Founded on the site of the 21 portals that opened up during an unknown arcane explosion, Junction is the largest city in the known realms, and the crossroads of the world.
The city has been built up and on the ruins of past cities, given the multiple skirmishes and wars fought to control this ground. These man-made ruins make up an undercity that hold relics of the past that can fetch a coin or two.
In the center of the city is Portal Park, a rectangular area where the 21 portals. Most of the portals are open to all use, though over time a chaotic system of queues has been put into place to allow the large caravans and every day traveler come to and fro from them all. In the center of the park is a large tower, that allows guards to keep an eye on all portals at once, and a company of the best fighters from every nation are on hand to be the first line of defense from any type of threat coming through the portals.
The city itself has grown out from Portal Park, though it is starting to grow vertically as well as new improvements make taller structures possible. It is ruled by a multinational council. Each of the major races have a seat on the council, as well as a seat for every nation where a portal ends up. Junction is a neutral territory, jointly held and ruled by all.