The bag actually contained a book, a bottle of Powerade, and a bag of Jelly Babies.
Many other locations were shot and were intended to be featured but the movie was overrunning by a wide margin so they were cut. These locations kept the route taken by Shawn geographically accurate.
The ruined building that Shawn is seen jumping through is known as the "Smuggler's Bothy" at Lamberton Skerrs and was built by the famous smuggler John Robertson in about 1760. He smuggled tea and was in partnership with a Swedish shipping line. The cover for the operation was fishing but the building was actually later used as a fishery cottage. It was eventually destroyed by vandals who set it alight.
The ticking clock sound effect used at the beginning is taken from Ennio Morricone's score to My Name Is Nobody (1973).
Shot entirely in natural light.