lakehead / ca / usa - beautifully d formations in shasta lake caverns national national landmark, northern

amazing america ancient attraction beautiful beautifully calcite california cave cavern caverns caves caving chamber colorful column dark decorated deep earth editorial formation formations geological geology hole inside interior karst lake lakehead landmark light limestone mineral mountain national natural nature northern old only rock shaped shasta speleology stalactite stalagmite states stone subterranean tourism travel tunnel underground united usa use water wet