The center of the galaxy. We can't see into the Milky Way's Galactic Core because the light is blocked by clouds of interstellar dust. It's theorized that the center of the Galactic Core contains a massive black hole. The density of stars here is about 1,000,000 stars in a volume with a 5-light year radius. That's six orders of magnitude more than what is seen in the Galactic Disk.

In the Worst Star Trek Movie ever, the Galactic Core is home to God, who needs a space ship.