While running around alien spaceships is a common sight in the show, it's the historical adventures that make for some of the most fascinating Doctor Who stories.
Sure, it's fun to see the Doctor exploring the sleek and shiny cities of the distant future, but there's a unique and arguably more interesting appeal in watching depictions of events that actually happened, in getting to know characters that actually existed.
To that end, Doctor Who has been all over the place. Victorian London, the Stone Age, Nazi Germany, ancient Rome, 1580s Venice, the North Pole: the show has visited many notable time periods and locations over the years, and this has resulted in the Doctor becoming directly involved with Earth history on more than one occasion.
From causing famous historical disasters to assisting some of the most pivotal points in the evolution of society, not a single series goes by without the Doctor interfering with human history in some way. And while this historical galavanting isn't always too notable, the Doctor has played with the past in some major ways every now and then.