The 12 Apostles
The cache, a camo-taped 35mm film pot, is hidden a little east of the Twelve Apostles (once known as the Druids Chair) - an ancient stone circle high up (381m) on Burley Moor near its boundary with Ilkley Moor and within the parish of Burley in Wharfedale. It is slightly below and northeast of an east-west ridge and approx 800m north-west of the Grubstones circle. Note: there is no need to move any larger rocks to find the cache.
To reach the cache (approx 45 minutes): park at the Cow and Calf parking area @ N 53 54.989 W 1 48.020 and make your way up the path heading straight up off the main flagged path towards the left of the rocky ridge. From here carry straight on to the stream (Backstone Beck) crossing @ N 53 54.868 W 1 48.403. Then head straight across and up the slope to the top of Rocky Valley and onwards to the path junction @ N 53 54.796 W 1 48.800. Turn left (south) here and carry on across the moor to the cache location.
The 12 Apostles of Ilkley Moor is West Yorkshire's finest stone circle. Alone on the edge of a high ridge of heather moor, it is quiet, windswept and a wonderful vantage point.
First highlighted on the 1851 Ordnance Survey map as a 'Circle of Stones' close to 'The Stone called Lanshaw Lad' (see GC866FK) it is one of the highest of all ancient monuments on Rombald’s Moor. It consists of the remains of a stone circle with a diameter of about 15 m which is thought to have been used for ceremonial purposes around 2,000 BC during the Bronze Age.
It originally had between 16-20 stones made from the local millstone grit set within a rubble bank, possibly with a central stone, but now has only 12. All of the stones were fallen by the mid-20th-century and were lying loose upon the ground. The circle was inside a bank 1.2 m wide and 0.6 m high which was still traceable in the 1920s but has apparently eroded since then due to visitors walking over the ground. At the centre of the circle was a small mound, which may have been the disturbed remains of a burial cairn.
In 1971 a group of amateurs made an unauthorised attempt to re-erect the fallen stones, but the stones soon fell again. They have since been re-erected at unknown times by unknown people. So it is unlikely that all (any?) of the stones remains in its original position.
The site suffers severe visitor erosion, as it was formerly hidden beneath heather, but is now in an area of bare trampled soil. Sadly, It is regarded as one of the most damaged prehistoric sites in West Yorkshire.
There are wonderful panoramic views from the stones and you can usually easily see the 'golf balls' of 
Menwith Hill (14 km NE) and (on a very clear day) the White Horse of Kilburn on the Hambleton Hills (53 km NE).
See here for a great short drone video above the 12 Apostles and The Cow & Calf rocks (added 21/6/19).
Various disputed theories have been suggested for the formation of the stone circle. There are many others on high ground not just in Yorkshire but across Britain and Ireland. Some have suggested it was a neutral ground at the junction of two ancient tracks for trading between tribes. Others say it was used as a druidical dial circle to observe the movement of celestial bodies which would allow bronze age settlers to identify when winter was coming or spring arriving to be able to start planting crops using shadows cast by the stones at certain times of the day.
Yet others are convinced that is was a more straightforward burial site. Interestingly on the summer solstice, as observed from the 12 Apostles, the sun rises directly above the Kilburn White Horse on the edge of the North York Moors, though oddly this figure was only created in the 19th century!
As with some other stone circles, there are reports of UFOs. One sighting took place in 1976. Three members of the Royal Observer Corps saw a white silent sphere hovering low over the stone circle while they were out on exercises. It remained motionless, then suddenly shot straight up into the sky eventually vanishing.
Two witnesses saw a similar light in July 1990. They were at the Backstone circle one night and saw a white 
ball of light on the horizon about a mile or so away. It approached the 12 Apostles from the west and when it reached the stones it became stationery. It then made a series of strange manoeuvres, backtracking at high speed, doing a 180° turn, returning to the circle before heading off to west where it had originally come from, apparently pursued by an Royal Air Force fighter which was seen heading in the direction which the light had taken.
See Mysterious Ilkley Moor for fascinating tales of the green man, UFOs and alien abduction! See also here for info on the stones. A Google search will locate several other relevant sites.
Added 16/7/20 - Across the Years Feature in the Wharfedale Observer of 7/11/19:
New twist to alien abduction on Ilkley Moor
A new twist has been added to a well-documented account of alien abduction on Ilkley Moor. Ufologist Nigel Mortimer, of Stocks Hill, Menston, has met two men from Horsforth who had an unexplained experience just 100 yards from where the incident allegedly took place. Mr Mortimer said: “They went for a walk just above White Wells at about 5pm on October 29, 1991. When they got to West Rock they found a great big ball of light 15ft across hovering above the rocks.” The men, who wish to remain anonymous, claim the ball of light then advanced and chased them for for a quarter of a mile as they ran back to Ilkley. This allegedly took them only ten minutes. Mr Mortimer’s attempts to get from West Rock to Ilkley have taken a minimum of half an hour. As a result he believes a “time warp” may have affected the two men.
