VISITORS to Castle Drogo on September 13 will be able to explore the castle free of charge, as part of the Heritage Open Days scheme. The castle will be open as normal throughout the day, though admission will be free. Drogo is currently undergoing a five year, £11-million renovation project to save the castle from major structural problems caused by serious leaks and water penetration throughout the building. The renovation work being done at Castle Drogo is on a massive scale. More than 64 kilometres of mortar joints need repointing, and all 917 windows of the property, made up of around 14,000 individual panes, need to be removed and repaired before being put back in place. This includes the single biggest window in any National Trust property. The property is remaining open to visitors throughout the work, though the ongoing building work will have a dramatic influence on what visitors will see when they visit. The braver visitors will get the chance to climb the scaffold viewing tower for amazing views of the valley below.