 In the 1830s , plans were drawn up to build the new London and Birmingham Railway . From an engineering perspective , the ideal route for the railway ran through the site of the castle , but concerns over the need to protect ancient monuments and buildings had been growing for several years , and the local Bridgwater estate were also keen to protect the local view from their buildings . The castle was ultimately specifically protected in the 1833 act that sanctioned the railway , forcing the track to take a route across the valley floor . Berkhamsted was the first building in Britain to receive statutory protection from development in this way . Nonetheless , the route still required the track to pass through the outer fortifications of the castle , a major engineering operation which was carried out in 1834 , destroying the castle gatehouse in the process . 
