Neptune is a big azure gas giant way out in the Outer Planets. It's distance from Earth and Mars made it inherently difficult to control, which has led to it becoming a pirate haven. The main colonized world is Triton, its largest moon. 

There are a smattering of cities on Triton, but the most prominent is The Trident. It's a domed platform held up by two massive tridents. Despite being controlled by pirates jockeying for supremacy, it's a surprisingly well-run, prosperous world. 

Notable Locations:

• Triton - by far the largest of the Neptunian moons. Home to The Trident, the pirate hotbed and a den of commerce, information dealing, and all manner of legal and illegal activity.

• Proteus - the second largest moon. this irregularly shaped world has little going on other than mining operations. There are rumors that the Pirate King Proteus has a secret base on the location bearing his name.