Holy Boys Cave is a large cave system on the Eastern side of Gibraltar.
Its entrance is a large tunnel like shoot heading down into the rock at an angle of around 45 Degrees.
There are many 'versions' or 'interpretations' by various 'local historians' over time as to why the cave is named 'Holy Boys Cave' but the one I have researched and which to me makes the most sense is the following:
I believe it was named by the 9th of foot regiment - who then became the royal Norfolk regiment on the 1st of July 1881. They were an infantry regiment who were nicknamed 'the holy boys' and were given the battle honor 'Gibraltar' for their service through the years of the great siege. They later joined with the Suffolk regiment to become what is now known to us as the 'Royal Anglian regiment'
They gained the "Holy Boys" nickname during the Peninsular War from the misidentification by a Spanish soldier of Britannia on their cap badge as the Virgin Mary.

Below is an extract from the book ‘History of the Royal Sappers and Miners’ – We believe this is the first recording of the discovery of the site on the 17th of August 1811.

‘In enlarging the works of the garrison, the military artificers frequently opened up cavities in the promontory which were mostly of sufficient interest to excite the curiosity of geologists; but one discovered in 17811, by some miners of the corps, while scarping the back of the Rock, attracted, at the time, unusual attention. It was situated on its eastern side, and its extent classed it among some of the largest within the area of the fortress. Removing the rank vegetation which had over-grown its mouth, a small chasm was bared, opening into a cave containing several chambers and grotto's, entered by narrow funnel-shaped crevices, some so low and winding that ingress could only be obtained by crawling through the long misty passages on all-fours. Seemingly, the roofs were supported by a number of pillars, which the dripping of ages had congoaiv^d [congealed?] into all shapes and sizes and into all degrees of hardness, from patches of soft silvered powder to the bold indurated [?] columnar stalactite. On the floors, at different heights, were stalagmites, some peering up like needles, and others, swollen and grotesque, rose from frothlike [frostlike?] cushions of delicate finish, which, "on being rudely touched, dissolved instantly into water". The hall at the extremity was divided into two oblong recesses, floored by a "deep layer of vegetable earth," where not a clump of the lowliest weed or a blade of grass was seen to show that vigor was in the earth.'" Nothing seemed capable of living there but a colony of bats, some flapping about on lazy wing, and others torpid; no process to be active, but the cold one of petrifaction, which, in nature's own confused method, had elaborated throughout the cavern, columns and pinnacles and cushions, jinflTs [?} and concretions, some as fleecy as snow, others as crisp as hoar-frost, and others of an opal hue as transparent as crystal. All
was rich, beautiful, and sparkling. It was a marvel to adventurers, but unfit for habitation; yet, in later years, this hole of the mountain was possessed by a Spanish goat-herd, who reached his solitude by the same threadlike but dangerous tracks as his goats. There might the recluse have lived till his bones fell among the petrifactions, but he was at length expelled from its gloomy precincts on account of his contraband iniquities’.

After reading this passage, I would also ask the question – Is this the first reference to ‘Simón Rodríguez Susarte?’