For three weeks at the end of the summer in 1937, the full fury of the Spanish civil war was concentrated on a small farming village a few hours northwest of Madrid. Belchite.
The Republicans (ie: coalition of loyalists, socialists, communists, anarchists and many others) first attacked the town to take pressure off the Nationalist (ie:fascists, rebels, German and Italian military support all led by Franco) advance elsewhere across the northwest.
Belchite was heavily fortified by 4,000 - 7,000 Nationalist soldiers, and it took days of siege warfare, finally ending in house-to-house fighting before the Republicans claimed the town.
A member of the International Brigade fighting alongside the Spanish Republicans, Bill Bailey described the fighting: We would knock a hole through a wall with a pickaxe, throw in a few hand-grenades, make the hole bigger, climb through into the next house, and clear it from cellar to attic. And by God we did this, hour after hour. The dead were piled in the street, almost a story high, and burnt. The engineers kept pouring on gasoline until the remains sank down. Then they came with big trucks and swept up the ashes. The whole town stank of burning flesh.
The Republican "victory" was to be short-lived. Days later, Franco's troops struck back and successfully dislodged the Republicans from Belchite with a combination of air and artillery fire. They also effectively destroyed the town.
This was not a unique outcome during the Spanish civil war, but for some reason Franco declared that Belchite was not to be touched after the war. By highest order, Belchite would not be leveled or rebuilt, rather it would stand as a reminder to the war.
Depending on your views of the war (and Franco), Belchite was preserved either as a reminder to the horrors of war, or a reminder as to what happens to villages that dare to cross Franco.
Almost 40 years after Franco's death and the remains of Belchite still stand, untouched since 1938. The ruins are hard to find, and there are almost no markers along any of the twisting back roads that wind through the nearby agricultural plains. But it is there, and you can visit, and you should.