Recent studies suggests the rocks appearance was caused by large scale earth movements which is not a part of the normal sedimentary process; however, this theory remains controversial.

In 2019, proposals to develop a 35 km2 (14 sq mi) 'West Anglesey Demonstration Zone' tidal energy project at South Stack were submitted under the Transport and Works Act 1992 to the Welsh Government for planning consent.

[4] Consent for the project, called Morlais was awarded in December 2021 and construction of the onshore grid connection works took place in 2023.

[5][6] As the development will come within 500 metres (1,600 ft) of the South Stack SSSI, concerns have been expressed about the visual impact on the Anglesey Area of Outstanding Natural Beauty and the Holyhead Mountain Heritage Coast, along with the resultant impact on the tourism, recreation and fishing sectors.

Most notably bottlenose dolphin and harbour porpoise would likely be affected, whilst razorbill and common guillemot will be severely impacted.

Travelling from the Breakwater Country Park, other sites along the way are the North Stack Fog Signal station, Caer y Tŵr, and Tŷ Mawr Hut Circles.

The cover photo for Roxy Music's Siren album was taken directly below the central span of the bridge on a slope on the south side, by Graham Hughes in August 1975.