All construction materials have to be taken across a treacherous stretch of sea and carried up a sheer cliff.

It was noticeable that the most treacherous stretches of pavement, with no grip, are those areas where my considerate neighbours have cleared the snow.

To add to the film's authenticity, they also plan to remove the modern ladders and ropes that have been permanently fixed along one of the mountain's most treacherous stretches.

Due to the array of separate tidal races produced by the underwater topography there are some treacherous stretches of water.

It features many technical challenges, including treacherous stretches with intervals up to an eleventh, numerous jumps in the left hand, repetitive chord strikes, and abundant octaves.