multi colored speleothems at the end of a dark gallery

multi colored speleothems end dark gallery fairy grotto cave stalagmite stalactite mine water colorful reflection lake mineral elf pond cavern dripping chamber sightseeing alum feengrotten fantasy subterranean underground iron satin speleology geology interior indoors famous place tourism travel destination idyllic tranquil scenic picturesque attraction saalfeld thuringia germany landscape horizontal no people low angle view grottoes