The Jar River, along with most of the northern coast of Jill, had been documented by explorers from various nations for hundreds of years. When Jill was thoroughly explored and founded in 1837, settlers followed the Jar directly south to Port Justin, Jill's first settlement and modern-day capitol. The Jar is considered the most important geographical feature of Jill, since it has shaped the territory so dramatically and is the backbone of the nation's three largest cities.