The Borgio Verezzi Caves — also known as the Grotte di Borgio Verezzi or Grotte Valdemino — are a karst cave system about 3 km from Pietra Ligure in the neighbouring municipality of Borgio Verezzi. The caves extend for nearly 1,500 metres through extraordinary stalactite and stalagmite formations, coloured in ochres and whites by mineral deposits. Guided tours take about an hour and wind through the most spectacular sections of this underground landscape.
The temperature inside stays around 16°C year-round, making it a welcome refuge from summer heat. The caves are open daily from spring to autumn, with reduced hours in winter. Combined with a visit to the old hilltop village of Verezzi above — which hosts a celebrated open-air theatre festival each summer — this makes for a rewarding half-day excursion from Pietra Ligure.