The Welsh island home to the solstice-aligned site Bryn Celli Ddu is Anglesey.
Bryn Celli Ddu is a Neolithic passage tomb near Llanddaniel Fab on Anglesey, off the northwest coast of Wales. Its Welsh name means “the mound in the dark grove,” an evocative reference to the monument’s setting and enclosed burial chamber.
The monument was once part of a larger ceremonial complex that included a henge and stone circle. Archaeologists excavated it in 1928–1929, and visitors can now enter the reconstructed mound through its stone passage. A decorated “Pattern Stone” and a central pillar are among its best-known features.
Anglesey is sometimes confused with other famous prehistoric-island settings, such as Iona or Skye, but Bryn Celli Ddu is specifically associated with Anglesey. The site’s astronomical interest comes from the passage’s relationship with the midsummer sunrise.