The Druid Stone

The Druid Stone is a natural rock formation with a narrow, manmade passage cut through its centre. It rises anomalously from otherwise gently undulating agricultural land close to the village of Blidworth, Nottinghamshire, in the heart of Sherwood Forest.

Composed of a conglomerate of pebbles and sand bound together with limestone, the Druid Stone, also called the "Altar Stone," stands over 13 feet (4 metres) high in a field of cows, sheep and alpacas. Formed by an eroded glacial deposit, the monolith dates back thousands of years, possibly used as a Druidical altar, though there's no evidence to back that up.

A 6-foot (2-metre) passage is cut out of the base of the rock, which is theorized to align with the May Day sunrise, possibly hinting at a link between the stone and the fertility festival of Beltane, a traditional Gaelic May Day festival held between the spring equinox and the summer solstice. 

According to local folklore, sick children were passed through the hole in the Druid Stone in an attempt to cure childhood illnesses such as whooping cough or rickets, with speculation that the act of passing through the stone symbolised the rebirth of a healthy child. The curious alignment of the passage with the sunrise during Beltane hints that this fertility festival was of particular significance to whoever carved the enigmatic passage, and the relatively recent use of the stone as a symbol of rebirth suggests a latent continuity of pagan belief at the site.