Ny-Ålesund, Norway, is a small company town, owned and operated by the company Outer Bay Shipping. Both it and the company are connected to The Dark. It is notable for being the northernmost human settlement on Earth except for research installations - where during the winter, nights last a long time.
On March 11, 2015, a gathering of The People's Church of the Divine Host in Hither Green Chapel was interrupted by Mark Bilham, who saw them singing with their voices repeatedly coming together for the words "Ny-Ålesund". Comments made by Natalie Ennis, a member of the Church, implied they were soon performing the ritual to bring The Dark into the world.
Basira Hussain later did further research into these events and discovered that around the same time there was a total solar eclipse in Ny-Ålesund. The last one had been 300 years ago, which matches how long Natalie had said the Church had been waiting for - presumably the last attempt at the Dark's ritual. She then began to say something about the relationship between Edmond Halley and John Flamsteed being connected but was interrupted.
In 2018, Jonathan Sims and Basira Hussain travel to Ny-Ålesund on false information that The Dark are gathering for another ritual. They encounter Manuela Dominguez and John destroys the Black Sun being kept there.
In Real Life
Ny-Ålesund is a real town on the island of Svalbard, Norway. It is a research town owned by the company Kings Bay. It is the northernmost functional civilian settlement in the world.
A solar eclipse really did happen there on March 20, 2015, with Ny-Ålesund in the path of totality. There was also a solar eclipse on May 3, 1715, famously predicted by Edmond Halley, but it was not a total eclipse in Ny-Ålesund. (See here and here for maps.)