Pillbox

There is a list of possessions auctioned after her death – her pillboxes and playing cards, two silver-mounted ivory lemon-squeezers.

Source: wiktionary

It was reported that the Germans had established trench works in front of the pillboxes. The enemy was said to have taken refuge from American fire in the pillboxes, later emerging to take up the trench positions.

Source: wiktionary

Beneath the wide steppe sky women in white kerchiefs were digging trenches and building small pillboxes, looking up now and again in case 'those vermin' were on the wing.

Source: wiktionary

"For the first time in 125 years a powerful enemy was now established across the narrow waters of the English Channel. ... Many people must have been bewildered by the innumerable activities all around them. They could understand the necessity for wiring and mining the beaches, the anti-tank obstacles at the defiles, the concrete pillboxes at the cross-roads, the intrusions into their houses to fill an attic with sandbags, on to their golf-courses or most fertile fields and gardens to burrow out some wide anti-tank ditch." So wrote Winston Churchill in Their Finest Hour, published in 1949.

Source: wiktionary