Io

One of the four Galilean moons of Jupiter, and one of the most important worlds of the Outer System. It has been successfully terraformed - although it is widely believed to be one of the most unpleasant worlds known to Mankind.
Regardless of that - or, to be more exact, because of that - the Iron Pact has successfully transformed it into the center of its heavy industry. It's already a hellish place, no ammount of pollution can make it worse.

Geography

Majority of Io's surface are large plains with an altitude variations of up to 2km. The only major exceptions to that are numerous volcanoes (some as tall as 8km) as well as occasional depressions.
It also has an ocean, albeit one that (due to the tidal movements caused by Jupiter's presence) has waves ranging up to several hundred meters, making the coastal areas rather inhospitable and forcing the settlements to be constructed on higher ground and at the slopes of the active volcanoes. Which erupt regularly, coating the entire regions in ash and forcing every settlement to reach highest levels of earthquake resistance.
Not to mentioned appropriate earthwork to direct lava and pyrocrastic flows away from them.
If that wasn't enough, those eruptions are massive enough to damage the fragile atmosphere of the planet, causing heat to rapidly evaporate from the area (together with some of the atmosphere) after each eruption. Eventually, the damages will repair on their own, although typically not before the volcanoes' surroundings are covered in deep snow.
There are also very common earthquakes, and an occasional firestorm caused by the volcanic eruptions setting a large, near-surface sulphur deposit aflame (while also spawning a lot of sulphur dioxide to choke everything in the vicinity). Needless to say, Io isn't a pleasant place to live.

Ecosystem

No, not really, at least except for algae, lichen and fungi that's used to aid the Sidhe's wondrous nanotechnology by changing carbon dioxide produced by the volcanic eruptions into oxygen.

Climate

Just like Ganymede, it is noted to have heavy cloud coverage all year along, with blue sky being a rare sight.

Natural Resources

Io has rivers of sulphur, high volcanic activity, a very limited hydrosphere and the atmosphere that (due to volcanic eruptions damaging its outer shell regularly) is periodically getting replaced. As a result, it's practically speaking a perfect Mining/Industrial World.
It has a lot of resources present at the site, there's no need to worry about the environmental damages, you have much more available space than in any space station (even despite the settlers needing to pick the location of their colony very carefully) and almost limitless geothermal energy alongside some chemical components that are easy to gather from the surrounding area.
In the end, building anything on its surface requires massive investments, but once its properly constructed, it will eventually pay back tenfold.

Summary
Distance from Sun: 778.57 mil. km
Distance to Jupiter: 0.422 mil. km
Diameter: 3643 km
Solar Constant: 0.073
Mass: 0.015 Earths
Gravity: 0.183 g
Mean Density: 3.528 kg/l
Day Length: 1.769 Earth days
Year Length: 11.862 Earth years
Rotation Axial Tilt: <10 degrees

Avg. Temperature per Latitude
poles: 13 C
75 deg: 14 C
60 deg: 15 C
45 deg: 15 C
30 deg: 16 C
15 deg: 16 C
equator: 16 C

Astrography

Object Type: Terrestrial Moon
Object Subtype: Hell
Primary Location: Core Sector
Secondary Location: Solar System
Tertiary Location: Jupiter Subsystem
Transshipment Station: Himalia

Habitation Status

Status: Colonized
Classification: Industrial World
Population: ~14 mln.
Capital: Nieuw-Amsterdam
Government: Iron Pact
Solar Commonwealth Member: Yes.