WW1 trench warfare. Trenches generally had pillboxes which could be described as defensive structures, and the entire trench warfare was about slowly building these defensive structures towards the enemy.

Tunnels were part of this too along with defensive counter tunnels. These go back a surprisingly long way and it’s worth reading the Wikipedia page for the ancient Greek account of tunnel warfare. The way they detected enemy tunnelling activity is clever.

Modern offensive tunnels pop up in the news regularly in the Israeli/Palestinian conflict and occasionally with Noth Korea too. https://en.m.wikipedia.org/wiki/Tunnel_warfare

Since you mentioned the Greeks, anyone with the slightest interest in Ancient Greece should read “A War Like No Other” by Victor Davis Hanson. It’s a fascinating account of the Peloponnesian War. There’s a chapter on siege warfare.

The closest real life has come to that is to assemble siege engines (like trebuchet) on the battlefield before use.

Actual turrets on an active battlefield? Not against a modern military, but maybe something like this: https://mwi.usma.edu/wp-content/uploads/2016/11/Spencer234.j...

> does any[one] have any examples to prove me wrong?

Perhaps NATO [0] in:

- Turkey (1952)

- Poland, Hungary (1999)

- Estonia, Latvia, Lithuania, Romania, Bulgaria, etc (2004)

- Ukraine (2017)

...might qualify as this tactic?

"The North Atlantic Treaty Organization was created in 1949 by the United States, Canada, and several Western European nations to provide collective security against the Soviet Union." [1]

[0] https://www.nato.int/nato-on-the-map/

[1] https://history.state.gov/milestones/1945-1952/nato

(EDIT: Formatting)

Early siege towers were basically what you'd consider a watch tower, but on some kind of rollers.