|Looking north, towards Swansea|
One of the quirky architectural highlights on the east coast of Tasmania, Spiky Bridge was built in 1843 by convicts from the nearby Rocky Hills Probation Station. Readily-available convict labor built much of the early 19th century infrastructure of Tasmania.
The going theory is that vertical flagstones were placed in this fashion at the top of the bridge to keep cows from tipping over the side into a drainage gully. The retaining wall is low, and this might have been a resource-saving method if the supply of flagstones was short. Every English speaking country has its rustics, and Tasmania has a reputation much similar to Newfoundland in Canada. Perhaps local cattle have the tendency to throw themselves over walls?
Another guess is it was a form of protest by the convict laborers. I prefer to think the convicts were just employing a little creativity to brighten their otherwise monotonous existence of hard work.
The odd "spiky bridge" is located 7.5 km south of Swansea, just off the western side of the Tasman Highway (A3). On the shoreward side of the road are secluded beaches overlooking Great Oyster Bay and the peninsula of magnificent Freycinet National Park. We visited here in February of 2009.