Lligwy is a Neolithic burial chamber in near the east coast of Anglesey. Consisting of a circle of upright stones, made into a low chamber by a very large roof slab which is estimated at 25 tonnes. Excavation in 1909 found the remains of 15 to 30 people, and pottery suggesting a late Neolithic dating period. During excavations in 1909 they had discovered artefacts in two separate layers, indicating that the site was used during two separate periods. These days the chamber is in the trusty hands of Cadw and open freely to the public all year round barring a few Christmas and New Year dates.