So, there were railways, maintain through elemental forces. However, in the intervening years, most remnants have been swept sway (bridges over the river washed away in floods, the metal scavanged etc. In this case, the rail system within the woods still exists and the players can find an ancient engine with the bound elemental still within so they can use it to go to the next encounter.
During the height of the Empire's days, the majority of Aeirglos was under the rule of the Empire, with only the upper north western, and far western portions remaining independent from the Empire's Rule.
The Empire of Karhielorhn fell into ruin approximately 250 years ago, and had a level of technology that rivaled anything known today. With the collapse of the empire, the humanoid hordes soon overran the scattered human settlements.
The Empire's infrastructure was based almost entirely on a reliance of contained elementals (earth elementals for construction & mining, water elementals for sewage & irrigation, Fire elementals for heating, smelting, Air elementals for transport). Eventually this huge reliance collapsed, resulting in the destruction of the capital of Branshoon. Larger cities were able to hold of most of the hordes, and soon fell into city states. Somehow the collapse of Branshoon lead to the release of the elemental that the empire relied upon.
At this time, a huge vortex of unknown magical energy surrounds occupies the sky above where Branshoon stood, and is visible from about a hundred miles out of the city. No one has ever reported entering the vortex to discern what lies beyound.