The primary and largest continent on Crucibal, Sejanna was named after the Iparian explorer who chronicled his journeys across the continent in the Iparian Age.
Sadly, his chronicles are lost to the ravages of time, but the land still bears his name.
Modern Sejanna (circa 2470 AT) is divided into three parts, Eastern, Central, and Western Sejanna.
Western Sejanna is the most well-known. To the north is Lor Pando and some unexplored regions. To the immediate east of Lor Pando is The Vale which is the home of the Magocracy of Thraxx-Arkana. South of Lor Pando is the Gruul Mountain Range, home of goblinoids of every kind and the hideout of every outlaw. East of that is the Ivrian Kingdom, ruled currently by King Enitharmon IV from the capital city of Iv. The Ivrian Kingdom rules from Frontier (just south of the Vale) to Last Bastion (south of Andrist) to the Barrier Wall, beyond which is Orcus.
To the south is Orcus and to the southeast is Proteus in what was once Edgeriven County. These lands are rife with oozes, slimes and undead as well as demons and their ilk.
Central Sejanna has vast unexplored lands to the north, in the central zone are the Wyrmlands, a vast desert and rocky wasteland where dragons dwell. South of that place is New Iparia, a small kingdom ruled by King Arpad V from the capital city of Iparios.
South and east of New Iparia is what once was called the Savage Forest, now it is the home of the liberated Radiant Elves and they have renamed their homeland: The Radiant Forest. That was in a happier time. Now the western half of the forest is overrun by demons and undead. The radiant elves make a valiant stand against their incursion in the eastern half of their realm.
Eastern Sejanna is crowned in the north by the Tyrus Empire ruled by The Imperial Council of K’zinti from the capital city of Tyrus. Tyrus sits on a monolith mesa dominating the surrounding flatlands. Access is by dumb waiters which constantly move about on its many cliff-faces. This place is inimical to magic since they blame the ancient Omniscientists for the present state of affairs in Sejanna. Any spells cast within their realm are dealt with immediately and severely. There is a profession called Tyrus Arcanamach which spends their time hunting down mages and sorcerers for the government. Clerics and druids are exempt from this harsh ruling.
On the Eastern Coast is the Blood Coast a haven for pirates, buccaneers and other scum. They are often visited by scouts looking for mercenaries to send west for the Undead War.
On the southeastern corner of Sejanna are the little-known Volturnian Marshes which span for leagues on end. In the midst of these fetid algae-ponds and cypresses is the lonely Free-City of Saltmarsh. No one knows much about it, but the pirates of the Blood Coast won’t touch their merchant ships.
Sejanna is currently affected by The Dark Firmament caused by the Doomed Ritual of Aristobulus the Balor wielding the stolen Wand of Orcus on year 0 of The Dark (2140 AfterTime). As to whether other continents on Crucibal are also affected by this Darkness, no one knows at this time.