Observation post
Observation posts are facilities for direct observation of a site. They are set up on high ground and used to be practically the only way of observation. Electronic aids are more common today.
Since the Middle Ages, military observation posts have mostly been stationed on castles with a mutual view, and in earlier times on prominent elevations (see e.g. Wachtstein ). Later they were of importance for large-scale enclosures, as in 1870 in front of the fortress of Metz and in front of Paris.
In the Russian army even portable observation towers were used at the beginning of the 20th century ( Wildgrube system ). The height of these dismountable towers was 25 m, the weight of the entire material about 1,600 kg. A command of 16 people trained for this service took 15 minutes to erect and 10 minutes to dismantle the tower. The field of view was up to 15 km.
