Dragon Gulf

The biggest gulf on the planet of Naldu, famed for its tumultuous weather and frequent natural disasters, was named Dragon Gulf after a local myth which attributes the storms to an evil dragon spirit Gerthyon. The gulf lies to the east of the city-state Occrea, which is often affected by storms which originate in the gulf, and has had to develop force field technology to shield the city's infrastructure and residents.
Before Occrea became a city-state, the region contained the city of Occrea and many smaller cities that were subsequently subsumed by it and became districts of Occrea instead. Until then, the geography of the region was quite different.
The Dragon Gulf used to be significantly smaller and located much further away; the weather was much less severe and only affected the small village communities on the coast. However during Occrea's transition to independence, the biggest earthquake on record in the region resulted in a huge chunk of coastland subsiding, swallowing an entire small nation and reforming the Dragon Gulf to what it is today. The region between the modern gulf and modern Occrea, once home to the thriving East Crel Onar, is now officially known as The Onar Wastes, is abandoned due to the regular flooding. Very little of the civilisations that lived there remains today.
The Onar Wastes also goes by many unofficial names, such as The Dragon's Wrath, The Dragon's Dinner, etc. The disaster which changed the region itself has many myths, urban legends, and conspiracy theories attached to it, most related to the changing political landscape of the time. Even today many children are still told that Gerthyon the dragon ate the land as a punishment from the Other Side, though what the punishment was for differs greatly from one storyteller to the next.
The myth of Gerthyon originated as a small village tale, but thrived in the aftermath of the disaster and over time became subsumed by the local religions and popular culture. Occrea suffered mass destruction and huge death tolls in the handful of years following the disaster before it was able to develop its force-field barriers, and after each one the myth became more prevalent. Modern Occrean society, especially the upper classes, consider themselves people of reason and science, but Gerthyon is an outstanding anomaly that even the most self-described rational-minded citizens believe in whole-heartedly, even if they don't believe in anything else that has not been proved by science.