Earth was a planet in the Sol system whose native sapient species were primarily homo sapiens and homo reptilia, though they were by no means the only intelligent species to develop there. The twin planet of Mondas, it was the third planet from its sun and therefore also known as Sol III, though mainly to extra-terrestrial cultures. It was a planet in which the the Doctor had a "particular interest", and may even have been the origin of some of the Doctor's DNA. Certainly, it was the planet from which the Doctor drew most of his travelling companions. It was also a planet about whose complete history the Doctor had demonstrated expertise, often knowing minutiae about it and being able to sense which points in its history were able to be altered, and which not.
Locations come in all shapes and sizes. But we've made it exceedingly easy to figure out how to start looking up locations. Just go to category:locations, and start working your way down.
Wanna see whether there have been DWU stories set in your neck of the woods? A good place to start might be our categories about regional governments. Take a stroll through:
(And yes, we know there are more places than this in the world, but it's a start!)
We like to study the natural features of the DWU. So take a look at:
Sometimes, you want to look at places in terms of whether a specific incarnation of the Doctor has visited there. We've tried to make that easy by offering up a whole branch of categories under locations visited by the Doctor. Want to discover the planets visited by the Third Doctor because you thought he was exiled to Earth and never went anywhere? Or maybe you're interested in what cities the Tenth Doctor went to.
Sure, the Doctor spends a heck of a lot of his time exploring Earth. But quite a lot is known about the geography of other worlds, too. Check out category:locations by planet to visit places like Skaro's Ocean of Ooze, or the great Martian cities or places to see on New Earth.
You've heard of trainspotters? Well, we're street spotters around here. Seriously, we love our city infrastructure, but especially streets. Yes, we tend to care most about English streets, but believe it or not, we know quite a lot about how to get around streets in Buenos Aires, thanks to Torchwood: Miracle Day. (So that's one good thing about that series.)