Walking on the narrow edge of a railway bridge crossing a stretch of water would be scary enough. Imagine doing that in boots with chunky heels?
The Duchess of Cambridge found herself on the wrong side of the tracks alongside her husband when the couple made an impromptu stop to see a Canadian steam train.
After walking through clouds of steam to clamber inside the cab - and taking the chance to blow its whistle - William and Kate had to make the return journey but were left cautiously watching every step, during a visit to the tiny wilderness hamlet of Carcross in the Yukon.
The locomotive had stopped close to the end of a railway bridge that crossed a stretch of water and although the drop below their feet was not a long one, there was no rail to stop them falling.
But imagine doing that in heels?
Kate, who was wearing a pale grey cardigan coat by Canadian designer Sentaler, looked pretty fearless as she balanced precariously on the edge.
And luckily, all went well and the royal couple successfully crossed the wooden bridge over scenic Lake Bennett.
But why did they want to make such a daring attempt which wasn't on their official schedule?
It seems William wanted to get a closer look at the locomotive after hearing how his grandparents the Queen and Duke of Edinburgh had travelled in the last carriage, which was specially fitted out with a marble table for their 1959 visit.
Now isn't that sweet?