210 mm gun M1939
210 mm gun M1939 is a rifled breech loader or artillery model.
Overview
Type of heavy siege gun.
In detail
It is associated with Czechoslovakia.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“210 mm gun M1939 (Br-17)”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q1974888: 210 mm gun M1939
Consult the source