There are several different known types of portals in the world of Eluaria. It will behoove you to know of them - some are useful and relatively safe, while others may not be!*
Collegium-maintained conduits
The collegium at Sihirisium maintains a core group of mages proficient in the art of creating conduits between two physical points in the world, which are commonly referred to as portals. These portals allow for the transport of small groups of individuals from one location to another using portal beacons, ancient stone structures scattered across the world.
Each of the major settlements has one or more of these structures in place, and most retain the services of one or more “portal mages” to operate them at need for paying customers. The portals might also be able to be operated by player character mages with such abilities.
Portaling magic involves a great deal of energy, so portals cannot generally accommodate large groups of people and objects such as caravans, large vehicles, and armies. Even moderately sized groups might take more than a single mage to maintain a portal.
Portals are generally operated at the major cities - Miller Dale, Islefield, Aismir, and Elsir Vale. There are some destinations that are limited:
Portals to Sihirisium are generally limited to members of the college or the council. People seeking to travel to the island of Sihirisium are encouraged to travel by ship, but exceptions are rumors to be made…
Much of Ostia appears to be affected by some form of interference to portaling magics. This includes Cretaine, Bridian, Anduillan, and Jeskin, but rumors have surfaced that a portal stone exists somewhere among the Canary Islands. Perhaps it might be found and activated.
Tidehaven has portal stones that operate well, but there appear to be some difficulties between the current controller of the city and Sihirisium - the posts of portal mages in that location can be undependable at best. Thankfully, there are usually an abundance of ships in the Tidehaven harbor that are almost as reliable (if not nearly as fast…)
There is a portal stone located in the Dark Ire Swamp, near a small hamlet with a cottage dedicated to support a portal mage, but the college has been unable to maintain a mage here for any length of time, as it is not a pleasant place to live. So while most portal mages could provide portaling services to the Dark Ire, there are no guarantees that there will be passage back - it might take some time before a new mage comes along. Fair warning!
Similarly, there is a portal in the city of Khonam in Qoth, and while most mages can create portals to Khonam, most of the portals in the civilized portions of the world have blocked access from Khonam, so you might be able to persuade a mage to send you there, but you will likely have to find alternate means of travel to return.
Wild Portals
Wild portals are something of a natural or supernatural phenomenon in Eluaria. They are largely unpredictable and untrustworthy, and can sometimes be the ruin of those brave enough to venture into them.
Wild portals sometimes open of their own accord for short periods of time, while some others have operated for much longer periods, even years. How they are powered is a mystery subject to much debate among the educated at the College, but still largely remains a mystery. Where a given wild portal leads to can be a gambit. Many times, the wild portal will give hints as to the destination by offering glimpses through it of what lies in the immediate vicinity on the other side, but other times, the portal is opaque and mysterious.
Travelling by wild portals is considered extremely dangerous, and is wildly discouraged by the College and Council alike - and yet these portals also seem to draw the interest of a large number of these educated experts, despite the risk. Perhaps some of them lead to places of special interest?
Extraplanar Portals
There is little evidence to support the existence of established extraplanar portals lurking throughout Eluaria, but that does not stop the rumors of such things existing.
Extraplanar portals (in theory) would lead from Eluaria to other planes of existence, other worlds. Scholars suggest that this might be the means by which the dragons entered and left Eluaria, and perhaps even the demons.
New teachings at the College in Sihirisium are now suggesting that such portals might exist all over Eluaria, waiting only for the right person with the right talent to open them, but this is widely regarded as theory by many.
* OOC Note: Hey folks, listen. Our number one priority in Eluaria is to support great storytelling. Don't let portals limit you progressing the stories that you want to tell. Time is fluid and possibilities are endless. Everyone is saying there's no portal mage in Tidehaven? There was when you got there! How else did you arrive in Miller Dale so quickly? Don't have any ties to the Collegium but want to get there without the hassle of a prolonged boat ride? Nobody will doubt you if you explain that you paid the portal mage a little extra to recognize you as an upstanding member of that fine institution. ;)