Why is "East Tilbury Blockhouse" trending?

Wikipedia Overview

Coalhouse Fort is an artillery fort in the eastern English county of Essex. It was built in the 1860s to guard the lower Thames from seaborne attack. It stands at Coalhouse Point on the north bank of the river, at a location near East Tilbury which was vulnerable to raiders and invaders. It was the last in a series of fortifications dating back to the 15th century and was the direct successor to a smaller mid-19th century fort built on the same site. Constructed during a period of tension with France, its location on marshy ground caused problems from the start and led to a lengthy construction process. The fort was equipped with a variety of large-calibre artillery guns and the most modern defensive facilities of the time, including shell-proof casemates protected by granite facing and cast-iron shields. Its lengthy construction and the rapid pace of artillery development at the time meant that it was practically obsolete for its original purpose within a few years of its completion.