The Lyme Regis Phase IV East Cliff scheme completed in 2015 is one of the largest and most complex coastal protection schemes attempted in recent times in the UK. Thirty years in planning, the ground engineering, environmental, community and financial challenges of the scheme provide an excellent example of public and stakeholder involvement that will be followed by the industry for decades to come. The historic coastal town of Lyme Regis is situated in one of the most unstable geological settings in the UK and has suffered severely from the effects of coastal erosion and landsliding. Landslide activity and cliff retreat has damaged or destroyed many properties throughout the town together with roads, land and infrastructure. In the absence of engineering intervention the future for the town was bleak, with existing coastal protection structures reaching the end of their useful life, landslide activity increasing in response to more frequent extreme wet winters over the last two decades, and the threat of worsening conditions in the future due to climate change. The paper describes the cliff instability and erosion problem, the programme of studies carried out over many years to support the scheme development, the specific challenges and how these were resolved, and the main benefits and achievements of the project.