<?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">antiaircraft towers</topic></authority><related type="broader"><topic>fortifications</topic></related><variant type="other"><topic>antiaircraft tower</topic></variant><variant type="other"><topic>flak towers</topic></variant> <note xml:lang="en"><![CDATA[ Large anti-aircraft gun blockhouses used by the Luftwaffe in World War II to protect against Allied overflights, serve as air-raid shelters, and to coordinate air defence. They had concrete walls up to 3.5 meters thick and were considered invulnerable. ]]></note></mads>