One of the seven wonders of the ancient world was the Pharos of Alexandria, which became the prototype for ancient lighthouses. Situated on Pharos island at the end of the harbour of the new city, the structure was planned by Ptoloemy of Egypt , who died in 284BC, and was completed in about 280BC. Its base proclaimed that the architect Sostratus of Cnidus dedicated it to the “saviour gods” on behalf of navigators. Models show a rectangular, tiered tower 122m (400ft) high, in which fres of resinous wood or oil were kept burning. They were reflected by metal mirrors, supposedly designed by Archimedes (right, 287-212BC), making them visible for up to 50km (30 miles), an incredible distance for this time. If the mirrors were designed by Archimedes, they would have been an addition after the main structure was completed, about 40 years after the time ‘No Royal Road to Geometry’ drama set in 290BC. The lighthouse was devastated by an earthquake in 1324AD.