The People of Gibraltar
2019 - The 200 Caves of Gibraltar - Part 10

Martin’s Guard No.1
Martin’s Guard No 2 
Both mentioned in the World Heritage site document and described as having produced evidence of post-medieval activity.

McNeil’s Cave
See Harley Street Fissure

Mediterranean Cave
Described by Kenyon in 1911 as:
. . .  the great Mediterranean Cave discovered in August 1902 in the course of the Admiralty quarrying operations which is a remarkably fine cave containing stalactites and stalagmites of an infinite variety of form and size.
The cave was large enough to cause a bit of a stir and news of its discovery and was referred to as a “Mammoth” cave. Unfortunately, the word “Mammoth” had already been used for another cave and whoever it is that is responsible for cave naming in Gibraltar decided on Mediterranean Cave instead. Three months later it appeared in the London Illustrated News – till unnamed.

1902 edition of the London Illustrated News

Quarry work along the southern end of Sandy Bay – The large cave entrance can be seen on the middle left by the road

Inside the Mediterranean Cave (Moorish Empire Website – adapted)

Mediterranean Cave is listed in the 2018 - Heritage and Antiquities Act.

Middle Hill Cave
See Collin’s Cave

Monkey's Cave
William’s Cave
The cave is mentioned indirectly on an early French 19th century map of the Rock when it identifies a battery on the north eastern side of the Rock as a “Batterie de la Caverne”.:

(Late 18th, early 19th century -  - Barbie du Bocage - detail)

In 1841 a certain E.F. Davis in an article in the Metropolitan Magazine about his visit to Gibraltar is probably the oldest reference to the cave by name:
Dear old Gib! . . . how I long again to clamber up thy rocky sides as in days of yore; or bend adventurously over the yawning chasm, to watch the antics of the grim baboons inhabiting Monkey's Cave . . .
E.F.Kelaart also gives it a passing mention in 1846 while George Busk writing in 1868 describes it as follows.
Monkey Cave, a very large and shallow cavern, situated on the lowest terrace, about 100 feet above the present level of the sea, immediately beyond the last Europa Advance Battery, and also on the eastern face.
Monkey's Cave was used during the Second World War as an entrance to AROW Street, an underground tunnel constructed in 1942 and named after Lt Col Arthur Robert Owen Williams who was in charge of the place. It was used as a general store by the military. 

(With acknowledgement and thanks to Tommy Finlayson - adapted)

As with Gort’s Hospital and other underground mining elsewhere, the rubble was used to construct the section of the airstrip that sticks out into the Bay of Gibraltar.

Airstrip in the 1940s

Lt Colonel Williams is actually a man I ought to have known much more of when I was young. During the summer months much of my time was spent swimming in Sandy Bay. At that time direct access by car to this beach and to Catalan Bay was impossible by car as a landslide had destroyed the main road leading to that side of the Rock. Instead we invariable took a bus that bypassed the problem by using Williams Way – yet another tunnel which the resourceful colonel had constructed during the War.

William’s Way (Probably taken during or just after WWII)

While AROW street was under construction a convalescent hospital was built at its entrance facing the sea.

Starting work on the hospital

During the 1950s the building was used as Headquarters by the Royal Electrical and Mechanical Engineers. Monkey’s Cave is also surprisingly mentioned in the World Heritage site document. It is described as having produced evidence of post-medieval activity.

As regards Williams Cave I have not been able to find any information at all anywhere. All I can suggest is that given the above, its name might be yet another reference to Lt Col Arthur Robert Owen Williams.

Moor's Cave (Cueva del Moro)
The only Cueva del Moro I can find is a well-known one in Tarifa.

Moorish Castle Barracks Cave
The tallest Islamic castle occupying the largest walled area in the Iberian peninsular . . . and are still not sure when it was built with guesses ranging from the 8th century (impossible), the 11th (unlikely), the 12th (possibly) the 14th (perhaps the most likely).

The Tower of Homage atop the Moorish Castle precinct or Qasbah – The building in front is probably a British built barracks (1880 )

Unfortunately, that’s about it as I can find no evidence of a cave either within the Castle or any nearby barracks.

Mount Misery Fissure
I have no idea where this one is. According to Kenyon:
Mount Misery is a name now attached to a part of the crest of the Rock . . . 

Plan of Gibraltar showing Mount Misery on the crest of the Rock (1908 - Baedeker - detail)
. . . but according to a manuscript which appears to be of about the year 1767 (footnote - now in the possession of Major Harrison, Secretary, RE Institute) the name originally applied to describing the “new or south mole” . . . The Mole battery or high platform faced formally towards the NW but there has been a new one made lately facing about S, mounting ten guns by which it is greatly strengthened. In it is the remains of a very high square wall once called Mount Misery because the breaking down thereof was ordered as a punishment.

Rosia district near the South Mole – The large white building just below Parson’s Lodge was known as Misery Barracks   (Late 19th century – J.H. Mann)

Mushroom Cave
I can’t find anything at all on this one

"Nameless" Cave
What can one say other than . . . why “nameless”?
Its general location, however, identifies it as a cave on the east sea cliff face of Europa Point.

Plan showing the location of “Nameless” Cave as “E” (Undated and unattributed)

Nursery Cave
Completely at a loss

O'Hara's Cave
General Charles O’Hara was Governor of Gibraltar from 1795 to 1802. He is memorably remembered as having instigated the construction of the ill-fated O’Hara’s Tower at the very top of the “sugar-loaf” the highest part of the Rock.  It has been suggested that O’Hara thought the tower might profitably be used to monitor enemy ship movements in Cadiz unpardonably forgetting to take into consideration that the intervening mountains would block the view.  Which may or may not be true but it makes for a good story.

O'Hara's Folly (1840s - George Lothian Hall)

I can’t find much on this cave other than its name but in 1841 a certain E.F. Davis made the following comment:
During my residence in Gibraltar, many indeed were the attempts made by officers, both military and naval, to follow the foot- steps of the brave old General 0'Hara whose exploratory researches had far out-stripped all others, and who, many years before, had left his valuable sword and watch at the extreme-point of his wanderings, as a reward to an courageous adventurer who should dare the dangers he had surmounted

General Charles O’Hara - aka” the Cock of the Rock“ (Christopher Bryant)

Could this have been the cave that bears the General’s name? Whether it was or not, the area where the Folly once stood seems well suited for the discovery of a cave

The view towards the north from O’Hara’s Folly (1824 - James Bucknall Estcourt)

"Operation Monkey" Cave
Not to be confused with Monkey Cave. 
During “Operation Tracer” - a secret War II plan which involved leaving military men behind on the Rock should the Germans succeed in taking Gibraltar - decoy projects known as “Operation Monkey” were also set up in both Coptic and Beefsteak Caves. The latter was even more confusingly identified as “Operation Monkey” Cave.

2019 - The 200 Caves of Gibraltar - Introduction
2019 - The 200 Caves of Gibraltar - Part 1 - All’s Well - Beefsteak
2019 - The 200 Caves of Gibraltar - Part 2 - Blackstrap - Buena Vista
2019 - The 200 Caves of Gibraltar - Part 3 - Cave S - Coptic
2019 - The 200 Caves of Gibraltar - Part 4 - Devil’s Fall - Devil’s Tower
2019 - The 200 Caves of Gibraltar - Part 5 - Europa Pass - Forbes’ Quarry
2019 - The 200 Caves of Gibraltar - Part 6 - Genista - George’s Bottom
2019 - The 200 Caves of Gibraltar - Part 7 - Gorham’s - Harley Street
2019 - The 200 Caves of Gibraltar - Part 8 - Holy Boys - Ibex
2019 - The 200 Caves of Gibraltar - Part 9 - Judge’s Cave - Martin’s Cave
2019 - The 200 Caves of Gibraltar - Part 10 - Monkey’s - O’Hara’s
2019 - The 200 Caves of Gibraltar - Part 11 - Poca Roca - Ragged Staff
2019 - The 200 Caves of Gibraltar - Part 12 - Spur Road - St Michael’s -
2019 - The 200 Caves of Gibraltar - Part 13 - Star Chamber - Viney Quarry