Editing Caltrop (section)

==Similar devices==
[[Image:Rozsochac.JPG|thumb|Czech hedgehogs deployed at the [[Stachelberg|Stachelberg fortress]] in Czechoslovakia in 1938]]
[[Punji stick]]s perform a similar role to caltrops. These are sharpened sticks placed vertically in the ground. Their use in modern times targets the body and limbs of a falling victim by means of a pit or tripwire.{{citation needed|date = December 2019}}

During the [[Second World War]], large caltrop-shaped objects made from [[reinforced concrete]] were used as [[anti-tank]] devices, although it seems that these were rare.<ref>{{cite web| url=http://www.britarch.ac.uk/projects/dob/crom1b.html| title=The 'Caltrop' as Anti-Tank Obstacle| publisher=British Archaeology| access-date=4 March 2006| archive-date=2005-12-20 | archive-url=https://web.archive.org/web/20051220132749/http://www.britarch.ac.uk/projects/dob/crom1b.html| url-status=dead}}</ref> Much more common were concrete devices called [[dragon's teeth (fortification)|dragon's teeth]], which were designed to wedge into [[tank]] treads. Large ones weighing over {{convert|1|tonne}} are still used defensively to deny access to wheeled vehicles, especially in camp areas. As dragon's teeth are immobile, the analogy with the caltrop is inexact. Another caltrop-like defence during World War II was the massive steel, freestanding [[Czech hedgehog]]; the works were designed as anti-tank obstacles and could also damage [[landing craft]] and [[warship]]s that came too close to shore. These were used by the Germans to defend beaches in [[Normandy Landings|Normandy]] and other coastal areas.<ref>{{Cite web|title=D-Day Beach Obstacles|url=https://www.d-daytoursnormandy.com/beach-obstacles-of-the-d-day-normandy-invasion/|access-date=January 1, 2021|website=D-Day Tours of Normandy|date=14 December 2019 }}</ref> [[Czech hedgehog]]s are heavily featured and plainly visible in the 1998 [[Steven Spielberg]]-directed American [[Epic film|epic]] [[war film]] ''[[Saving Private Ryan]]'', throughout the scenes early in the film depicting the June{{spaces}}6, 1944 [[Omaha Beach]] assault (part of the [[Normandy landings]] during [[World War II]]).

[[Tetrapod (structure)|Tetrapods]] are concrete blocks shaped like caltrops, which interlock when piled up. They are used as [[riprap]] in the construction of [[breakwaters]] and other sea defences, as they have been found to let the water pass through them and interrupt natural processes less than some other defenses.{{citation needed|date = December 2019}}