Another site I 'visited' today where I couldn't see a thing due to tall crops in the field. However, I did previously see a good reconstruction of the site in the Corinium Museum in Cirencester - excellent place to visit – highly recommended.
The eminent Leslie Valentine Grinsell spoke to a local farmer in Puesdown Inn in 1959. He told him that the older farmers in the area would say that when the plough went over one of these longbarrows, the ground sounded hollow.
The south barrow used to have 2 upright stones at its SE end, but these were gone by the 1920s. Got in the way of the plough probably. Oh well. But they kind of indicate the 'megalithic' nature of the barrow and hence that it might well have sounded hollow, maybe having a chamber inside.
Ocifant may not have been very impressed with the long barrows at Hazleton, but did he realise they feature in 'Raiders of the Lost Ark'? Surely that would have changed his mind. Well, perhaps not.
In the film Harrison Ford gives a lecture to his archaeology class about 'Turkdean barrow near Hazleton'. He says "This site demonstrates one of the great dangers of archaeology.. not of life and limb although that does sometimes take place.. No, I'm talking about folklore. In this case a local tradition held that there was a golden coffin buried at the site... this accounts for the holes dug all over the barrow..."
I've no idea if this common folklore motif really is attached to this barrow (a golden coffin is supposed to be at Windmill Tump, near a (different) Hazleton Manor). Lots of barrows have the folklore that they contain a golden object (though it's very rare that any actually do) so it's not surprising the film makers should mention this theme - all three films are about myth and archaeology are they not?
Perhaps the film makers chose Hazleton because the north barrow there was very comprehensively excavated - I suppose it must be a well known example of a Cotswold-Severn style barrow amongst archaeologists. The films all have some loose! basis in 'real' legendary subjects. But I don't think it was excavated until the 1980s! so Dr Jones in his 1930s university wouldn't have heard of it.