The ruins look peaceful because the argument is no longer audible.

Ruins are quiet now, and that quiet is the whole reason they feel serene. What stood there was contested, expensive, and full of people disagreeing loudly about what it was for and who it belonged to. Time removed the noise and left the shape, and we read the shape as peaceful because the argument is not available to us any more.

When a place or a period seems calm from a distance, assume the volume has simply been turned off. Look for what was fought over. It is also worth remembering when your own difficult stretch eventually goes quiet, because the calm afterwards will not mean it was easy.