Kleyun (Cleon)

A remote system rumoured to have a lost colony with formidable defences. The main world, Kleyun, is a garden world with abundant flora and fauna. The inhabitants are both belligerent and isolationist and approaching vessels are fired upon.

Illustration by Andrew Boulton via Flickr
Nb: may need to relocate the world so as not to be too close to others worlds, at least J4 is ideal though a nearby non-water & non-GS world would be acceptable as well.
Specific and unknown
The world is a garden world that is astrologically isolated from most other planets till the arrival of the IISS Bright Light on its extended long term scout mission beyond the Great Rift. The jump-5, Lightning class cruiser, arrived in system with a serious power plant leak that was irradiating the crew after years of basic maintenance.
The second planet appeared to be a paradise and the crew were evacuated there while engineers and techs struggled with the plant till, they were finally forced to jettison the core. Using emergency power the Bright Light crash landed and the scouts were marooned on their new world.
Being scouts they set up a thriving colony using the components of the ship and their varied and practical skills. It flourished for several years till it became apparent that the drew had been rendered infertile and would, with time, develop a wide, but ultimately terminal, range of cancers. Over the years the population dwindled and a raid by Vargr forced them to develop defences. Eventually the last crew person passed away and nature reclaimed Cleon but the formidable, automated defence systems remained. Two destroyed ships litter the system who failed to listen to the automated warning.
