This photograph was in "Death on the Hippie Trail," about events in rural parts of India and Nepal. What most interested me was the structure the boys are leaning against (click photo for larger image).
What I initially thought was a wall appears instead to be some type of pillar supporting a larger structure above. It appears to have been constructed using a combination of huge timber beams and large rocks. My guess is that the wood component provides a flexibility and shock-absorption that a purely-stone structure could not offer. The design has probably been empirically arrived at by multiple generations of stonemasons in an earthquake-prone area.
I think I have blogged something like this before, but at the moment I can't find the old post.
Addendum: Still can't find my old post (if it exists), but I'll offer a tip of the blogging cap to reader RolandT for providing a link about murus gallicus ("Gallic wall"), as described by Julius Caesar:
Straight beams, connected lengthwise and two feet distant from each other at equal intervals, are placed together on the ground; these are morticed on the inside, and covered with plenty of earth. But the intervals which we have mentioned, are closed up in front by large stones... each row of beams is kept firmly in its place by a row of stones. In this manner the whole wall is consolidated, until the regular height of the wall be completed.Here's a replica of a Gallic wall in Manching, Bavaria (photo credit Wolfgang Sauber):
... it possesses great advantages as regards utility and the defence of cities; for the stone protects it from fire, and the wood from the battering ram, since it [the wood] being morticed in the inside with rows of beams, generally forty feet each in length, can neither be broken through nor torn asunder.
I believe the image I embedded at the top is an example of Indian kath knuni architecture, best described in detail at this pdf and this slideshow.
Note the wood and stone are assembled without the use of any mortar. Impressive.