Pushta is the Hindi word for retaining wall. Living in the newest mountains in the world (which are still moving), there is a lot of need for them around this area. The first photo shows what most of them look like after surviving a monsoon.
This is a place that didn't have a pushta before the last monsoon, but will probably get one soon. You can see how crumbly much of the hills are.
This is a brand new pushta on the back side of the chakkar, not far from the new Lal Tibba overlook. The holes allow water to drain out during the monsoon, helping to prevent bulging and breaking.
This is the same place, showing how the construction looks.
Here's a longer view; this is one of the biggest pushtas around.
Here are the men working on it. Every stone is painstakingly laid by hand. If the rocks are too large, they are hit with hammers until they break apart.
In this photo you can see the pyramid shape of the pushta from the side.
The large one below Landour Hospital is making good progress. It is quite far out from the side of the hill; it looks like they are doing that to widen the road (you can see the crumbly edge of the road at the top of the work area).