Glacis

glacis

A sloped embankment in front of a fortification, so raised as to bring an advancing enemy into the most direct line of fire.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Glacis

 

a gently sloping embankment in front of the outside ditch of a fortress, long-term structure, or field fortification. The glacis was built for the purpose of improving the field of fire over terrain lying in front of it and for camouflaging and defending the fortification.

In Russian fortresses the main rampart sometimes had a glacis-like profile, so that frontal fire could be directed at the bottom of the outside ditch. In current long-term fortifications the glacis is not used, and in field fortifications (foxholes and trenches) a breastwork is set up. In architecture the glacis is the unbuilt space in front of a fortress (in front of the earth embankment or in its place if it has been destroyed). During a city’s development around a fortress, the glacis usually was turned into a garden or a square (for example, the Admiralty and Senate [now Decembrists] squares in Leningrad on the site of the 18th-century ditches and glacis of the Admiralty shipyard-fortress).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.