<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">polygonal forts</topic></authority><related type="broader"><topic>forts</topic></related><variant type="other"><topic>forts, polygonal</topic></variant><variant type="other"><topic>polygonal fort</topic></variant><variant type="other"><topic>polygonal fortresses</topic></variant> <note xml:lang="en"><![CDATA[ Forts having a polygonal shape, which varied according to the site and requirements. Although they existed by the middle ages, prime examples of polygonal forts were those constructed resist the fire of rifled artillery and heavy mortars in the late 18th through 19th centuries. ]]></note></mads>