Before leaving Sequoia to drive to Yosemite, we went to Crystal Cave - a collection of limestone caves described as "decorated with curtains of icicle-like stalactites and mounds of stalagmites". It reminded me of going through the caves at 'Cave Stream' when I was a teenager in the South Island of NZ (although without the getting wet wading through the river in the pitch darkness), Waitomo Caves and the Jenolan Caves in NSW near Sydney. Very cool but rather chilly inside!