This thesis examines the contentious legacy of brutalist architecture in Britain. Once the lingua franca of post-war architecture in the UK--demonstrating the principles of modernism advocated by high-profile European architects like Le Corbusier as well as socialist ethics--brutalist architecture's legacy in Britain today is both reviled and revered. The paper, by surveying three major buildings that are classified as "brutalist": Alison and Peter Smithson's Hunstanton Secondary Modern School, Erno Goldfinger's Trellick Tower, and Denys Lasdun's National Theatre, intends to demonstrate the enduring importance of brutalist architecture in Britain. By examining the difference between architectural history and architectural heritage, and by evaluating popular and professional criticisms of Brutalism, this thesis ultimately concludes that the preservation of brutalist buildings must be undertaken in order to protect an important chapter in the history of architecture and planning in the United Kingdom.