1931 - Calais Tour du Guet Light in France declared Historical Monument.

The Tour du Guet (watchtower) dates back to at least 1302. It served as the main Calais lighthouse from 1818 to 1848, and was declared a historical monument in 1931. The appearance of the medieval tower has changed considerably since World War II.
http://www.lighthousedepot.com/database/uniquelighthouse.cfm?value=5323

Bert

No mountain is too tall if your first step is belief. -Anonymous