Ellin's Tower is the information centre - open from Easter to September - of the RSPB's South Stack Cliffs reserve on the Isle of Anglesey. The cliffside nesting colony includes razorbills, guillemots and puffins. There are several paths through the reserve which covers most of the north western end of Holy Island from Ellin's Tower to North Stack, including Holyhead Mountain. Contact phone number for the reserve is 01407 764973.