1) Medieval architecture 
Putlog holes or putlock holes are small holes in the walls of structures to receive the ends of poles (small round logs) or beams, called putlogs or putlocks, to form scaffolding. Putlog holes may extend through a wall to provide staging on both sides of the wall. A historically common type of scaffolding, putlog holes date from the ancient Roman ...
holes left by the withdrawal of timbers used to secure scaffolding
A hole intentionally left in the surface of a wall for insertion of a horizontal pole.
A hole intentionally left in the surface of a wall for insertion of a horizontal pole.