Craig yr Aderyn, also known as Bird's Rock, is a hill in Gwynedd, Wales, rising 258 meters above sea level. It's got an Iron Age hillfort and is a hotspot for birdwatching, especially choughs. The place is owned by Snowdonia National Park Authority and is home to various bird species like cormorants and peregrine falcons. Plus, it's got some cool cultural ties, like being featured in Susan Cooper's book "The Grey King." So, if you're into nature and history, Craig yr Aderyn is definitely worth checking out!