Defence structure
Defintion
Umbrella term for fortifications that were either purposely constructed in the water or that were once terrestrial and became inundated as a result of sea-level change.
Description
A barrier can consist of oblique or vertical wooden piles, stones or log coffins filled with stones [1] A sea barrier or harbour facility can be integrated in a wider defence structure.
Part of pile defence structure at the site Raasepori of castle in Finland. Photo: Sallamaria Tikkanen, Finnish Heritage Agency.
Underwater defence structure at Suomenlinna, Helsinki, Finland. Photo: Maija Huttunen.
- ↑ Guide for Archaeological Heritage in Finland: underwater defence structure: http://akp.nba.fi/wiki;vedenalainen-estevarustus