 In 1973, four years after the discovery, the inside of the cave was developed for observation and it was opened to the public.A notable feature of Abukuma-do is the existence of boxwork, a rare cave formation composed of thin blades of the mineral calcite that project from cave walls and ceilings, forming a honeycomb or box-like pattern.Boxwork can also be found in Shimukugama in Okinawa and Sugawatari-do (氷渡洞 - Ice Cross Cave) in Iwate Prefecture, but because Abukuma-do is currently the only limestone cave in Japan open to tourists, it is subsequently the only cave in Japan in which boxwork can be seen.