Crawling in and out of graves isn't everyone's idea of a good time. For those willing to give it a try, though, Yoshimi Hyakuana in Saitama Prefecture makes for an interesting day trip out of Tokyo.
Literally meaning, "100 holes of Yoshimi," the Yoshimi Hyakuana National Historic Site preserves 219 ancient tombs carved into a soft sandstone hillside between the sixth and seventh centuries.
After the holes were rediscovered in the 1880s, the first Japanese archaeologist to work there believed they had been cave dwellings. However, further research in the 1920s showed they were burial sites.