Siege mentality
In medieval times, town and castles were built with heavily fortified stone walls, towers, and walls within walls, to make them easier to defend, but attackers found all kinds of ways to breach the walls.

Own Goal
Underwater warfare began in the 19th century. The effective submarine attack was made in 1864, during the Confederates H.L Hunley fired a ram torpedo and sank an enemy ship. Unfortunately, the explosion blew up the submarine, too.

Tag :defender built
Tag :submarine attack