Before revision: The major difference between a modern blockhouse and a bunker is that a bunker is constructed mostly below ground level while a blockhouse is constructed mostly above ground level.For the difference between blockhouses and bunkers see , , The Admiralty Citadel in 2008 Some blockhouses like those constructed in England in 1940 were built in anticipation of a German invasion , they were often hexagonal in shape and were called "pillboxes".
After revision: The major difference between a modern blockhouse and a bunker is that a bunker is constructed mostly below ground level while a blockhouse is constructed mostly above ground level.For the difference between blockhouses and bunkers see ;, St James' Park, London, , The Admiralty Citadel in 2008 Some blockhouses like those constructed in England in 1940 were built in anticipation of a German invasion , they were often hexagonal in shape and were called "pillboxes".