another and closer view of Spikey Bridge, Swansea.

The reason for the spikes remains a mystery
The reason the spikes were included in the design of the remains an enigma. One of the often quoted explanations for the spikes was to stop cows from falling over the edge, down into the gully. Some say it was to stop people jumping to their death, although the shallow ditch makes that seem unlikely. Another reason given is that when the bridge was built, the convicts responsible for the construction wanted to exact revenge of their supervisor and therefore stuck the rocks in the wrong way, starting a decorative trend that became responsible for the bridge’s name.
The jagged rocks have managed to bring ongoing attention to the Spiky Bridge as a part of Tasmanian history and people will no doubt continue to appreciate the humorous construction techniques for generations to come. Hopefully the lives of numerous wandering cows have been saved in the 177 years since it was built too.