The North side of Cliffe Fort, a Victorian artillery fort in Kent, England, built in the 1860s to defend the Thames approaches. The fort is now ruined. More information about the fort here:
https://en.wikipedia.org/wiki/Cliffe_Fort
A particularly interesting point about Cliffe Fort is that it was the first site in the World to have a Brennan Torpedo installation. The Brennan Torpedo was an amazing Victorian invention - a steam powered wire guided torpedo - launched from shore and used to protect fixed installations. Invented by an Australian it has a claim to being the World's first guided weapon.
Wikipedia entry for the Brennan Torpedo: https://en.wikipedia.org/wiki/Brennan_torpedo
Computer animation showing how the torpedo functioned : https://www.youtube.com/watch?v=sQJCOnyUvfU
This photogrammetery model was made from images shot by drone in 2021.
Another model of the whole fort here : https://skfb.ly/6AuxP
Located here:
OSGB: TQ 70630 76705
https://w3w.co/duck.limbs.cities