San Martiño Pinario

**Because cities are built on their own debris — and the ground rises by centimetres every generation.** ✅ **First mechanism — rubble**: **when a building collapses or is pulled down, its debris is not carted away** ⚠ **before modern times**: **it is levelled where it lies and built over**; **so every building cycle raises the level**. ✅ **Second — refuse**: **before sewers and rubbish collection**, **waste was thrown into the street, trodden down and accumulated**; ⚠ **continually raising the street**. ✅ **Third — repeated paving**: **the easiest way to repair a damaged street is to lay a new surface over the old** — **not to lift it**; **and each layer is ten centimetres**. ✅ **The result over a thousand years**: **two or three metres, sometimes more** — ⚠ **so old buildings' doorways sink**, **and churches come to be entered by going down rather than up**. ✅ **Examples abound**: **Ravenna's baptistery three metres below the street**, **the Temple of Minerva in Assisi with its bases buried**, **and this monastery in Santiago**. ⚠ **In Ravenna another cause is added — the land itself subsiding**; **here the cause is purely cumulative**.