The Streel River connects Darokin to the Known World. It is represents trade and commerce to the people of the Republic. Rock Home, Vestland, the Heldann Freeholds, Ethengar and Glantri all send their trade south on the Streel into the fortress port city of Corunglain. Corunglain is the last bastion of Darokin civilization before entering the terrors of the Broken Lands. Every south bound river captain gives a sigh of relief at sighting her shining towers. Every north bound captain says a prayer for safe passage to whatever god he worships once her docks are behind him.
Corunglain is the home base for excursions into the Broken Lands for all those brave enough to risk the dangers in search of fame and fortune.
The Broken Lands is set in the Known World as presented in X1 Isle of Dread. No other sourcebooks or gazetteers are being used.
The Sword and Wizardry White Box is the ruleset but there is an 18 page House Ruled Players manual here that is all you will need to play.