A small castellated stone tower built in 1868 by the local MP, John Stanley, as a summer house for his wife Ellen — "Elin" in Welsh. It now functions as the RSPB observation point above the South Stack cliffs, with windows facing directly onto the seabird colonies and a few telescopes for visitors.
This is the best place to watch the cliffs in spring and early summer without committing to the descent to the lighthouse. From the tower you can see all three of the cliff-nesting species side by side, and on lucky days the choughs that have recolonised this corner of the coast wheeling between the headlands. Entry is free.