During the construction of the Eastern Scheldt storm surge barrier in the 1970s and 1980s, 66 pillars were built for a lockable storm surge barrier. Ultimately, 65 copies were sufficient; one served as a reserve: constructing a pillar took a year and a half. Then, it was helpful to have a backup in case something went wrong.
Cathedral
After the construction of the Oosterscheldekering, the reserve pillar remained lonely in the water. The pillar at the Neeltje-Jans work island, popularly known as "the cathedral ", was used as a climbing wall for many years. The reserve pillar is, therefore, thirty meters high.
Lockable storm surge barrier