we went to castle urquhart when we were in scotland, and i noticed these two bikers who were wandering round dressed identically with their biker helmets and visors down.

it was like they were some aliens invading.

i imagine if they were aliens they'd not be too impressed by our housing, and urquhart castle is quite fally-downy.

wasn't there a doctor who episode like this ?

i think they were essentially peaceful. perhaps just stopping by for a bit of sightseeing whilst travelling between two distant planets (similar to the Italian tourists who were also there in abundance heading north through scotland)

eventually they left in peace

but i don't think they were the only aliens as this person was wandering round with a huge hood making her look like she was from Star Wars. she followed the bikers out of the castle ...