These acrobatic men are preparing a scaffolding eith long sticks of bamboo. The building is Ruvanvelisaya Dagoba in Anuradhapura. Originally built by King Dutugemenu140 B.C. it became a ruin and was renovated in early 20th century. It is now 103m tall. And these workers are working at a height of about 80-90 metres. I put a picture in the WS with a lesser zoom.