“The 30th October, 1981. Day before Hallows’ Eve, thirty-nine years ago. But — why is she? Oh.”
-- Scorpius Malfoy (CC4.2)
Aviemore Train Station is a muggle location in Scottish Highlands, about 45 miles from Hogwarts, where Scorpius and Albus get sent back to in 1981 by Delphi.
The Aviemore Train Station is where Albus and Scorpius end up after Delphi sends them back in time to 1981. They find out that it's the day before Voldemort killed Lily and James Potter, 30 October 1981.