In the super distant future, or maybe the past, or something something sci-fi-ish, exists a universe of nothing but war and fighting. Yada-yada grimdark fantasy. Regardless of lore, terrain makes the fights more enjoyable.
28mm scaled trenches.
PRINTABLE (HORIZONTAL AND VERTICAL)
FITS SMALL FORMAT PRINTERS! (~100mm x ~100mm minimum)
CHEAP! (Don't buy large sets that you'll never print half of!)
So whether you pray to your preferred emperor, king, chaos gods, or just like to go to WAAAAAGH*cough*WAR; print some trenches and enjoy the fight.