Abukumado Cave of Fukushima prefecture is an accessible cave with a number of interesting geological features. Spanning a length of over three thousand meters, the available length that has been rendered suitable for exploration is around six hundred meters. In this expanse, you will be able to see the "Christmas Tree" stalagmite, which is assumed to be the largest stalagmite in all of Asia. A slightly tighter, 120 meter long exploration course that will bring you through narrower tunnels and be more challenging to traverse can also be accessed.