Secret one
This secret area is located in one of the cars of the train - it contains two treasure items (which appear to be gold bars, but which intelligence believes may actually be foil-covered chocolate - handle accordingly).
The treasure is in plain sight from beside the train, but it isn't possible to climb in from ground level. Instead, you need to enter the building beside the train and eliminate any opposition you encounter there. Once that's done, make your way to the roof section that overlooks the train:
From here, jump up onto the wall and banister above the train
You'll see from here that there's an open hatch on the roof of our desired traincar - jump down onto the train (you'll take a little damage from this)
and then enter the train via the hatch
Secret two
In the warehouse, you'll find this area
Ideally, friendly Fritz the guard would move that moving platform over for us, but he's not playing, so we need to climb up on the banister
and sprint-jump over ourselves (the picture below shows the view back over the void which we've just jumped):
then jump over to the fixed platform - before:
after:
lastly we can thank Fritz personally for his unhelpful attitude and enter the secret area
This document is Copyright © 2001-2011 W.Finlay McWalter. Thanks to many generous contributors.
Rights to copy, modify and distribute are as specified in the Open Content Licence.