Palm Beach

Lucerne, 20 million years ago.
Fossilized sea shells. Twenty million years ago they were swept onto the sand beach in their thousands.	The ripples in the sandstone were shaped by waves and currents in the loose sand before turning to stone. Such ripples are usually formed near coastal areas.
The (positive and negative) imprint of a palm leaf proves that the climate in the region where Lucerne stands today was indeed once subtropical.