Doune Castle is relatively close to both Edinburgh and Glasgow. As such, it is perhaps not the most famous castle in the Lowlands, but also not unknown. Fans of both Monty Python or the Outlander will recognise it even more, and for the Outlander people, I found this a lot more spectacular than Blackness Castle.
I am not familiar enough with Monty Python to comment on that side, but I will mention both Outlander and another series here. Firstly, however, the story of Doune. Another castle which was quite important in the 14th century; Albany or Menteith, Robert Stewart, was the lord of this castle and his ambition was boundless. As the audioguide in the castle (btw, a very nice addition though not quite the best thing in case we’re dealing with a rainy day) mentioned, however, we can consider him lucky for dying in 1420, a few years before King James I, in whose name he reigned, being restored to full power. Doune became a royal stronghold, and more than a hundred years later, the name of Mary Queen of Scots was associated with the top level apartments in the tower (though it isn’t even known whether she actually stayed here).
The Outlander bit is epic. Castle Leoch is the Doune Castle in Invernessshire. The kitchen from Doune is the kitchen in Leoch. Admittedly not all of the scenes were filmed here, but it’s close enough with the film-company making an exact replica of the set for the filming. Admittedly, with the audioguide introducing this aspect by bringing in the Outlander’s actor for Jaime, this could have been more iconic. I found him a bit lacklustre in most aspects with no real enthusiasm showing in his words.
What is mentioned in fewer places is the fact that Doune was also used for the pilot of the Game of Thrones. It’s not quite the same which made Winterfell in actual Episode 1, but there are definite similarities. It is a pity they didn’t show Doune more in those final scenes, but one can see the local features in what they created for the final set of Winterfell.