There was a structure, perhaps of bones, faintly visible under the skin.
As of 2006, this seems to be enforced, with no visible new permanent structures being built within the preceding year.
St. Mary's Tower is the most visible structure on the island.
A visible structure needs to be given to your notes which reflects the analysis you have brought to the subject matter.
The vertical structure visible in the photograph is the lift scaffolding.
The Vincindières built many of the structures still visible at the site.
It can be any structure barely visible by light microscopy.
Significant parts of the Roman wall remain, though most of the visible structure is later.
The structures currently visible are mostly from the 18th century.
Bathed in colored lights, it's the only structure visible at night for miles.