Aerodrome runway at Turnberry. Many courses have pillboxes.
Here are temporary rules (1941) from the Richmond Golf Club in London.
1. Players are asked to collect the bomb and shrapnel splinters to save these causing damage to the mowing machines.
2. In competitions, during gunfire or while boms are falling, players may take shelter without penalty or ceasing play.
3. The positions of known delayed action bombs are marked by red flags at a reasonable, but not guaranteed, safe distance therefrom.
4. Shrapnel and/or bonb splinters on the fairways , or in bunkers, within a club's length of a ball may be moved without penalty, and no penalty shall be incurred if a ball is thereby caused to move accidentally.
5. A ball moved by enemy action may be replaced, or if lost, or destroyed, a ball may be droped not nearer the hole without penalty.
6. A ball lying in a crater may be lifted and dropped not nearer the hole, preservng the line to the hole, without penaly.
7. A player whose stroke is affected by the simultaneous explosion of a bomb may play another ball. Penalty one stroke.
This says something about the fortitude of golfers and the allure of the sport.