Mehmansary of Nayin 1967:

Undoubtedly Keyvan's most successful project remains Mehmansaray Nayin, an inn he designed for the ministry of tourism in the historic city of Nayin, in the province of Esfahan, located on the main highway between Esfahan and Yazd in 1967. Inspired by local traditional architecture, economically built by local craftsmen, it is a building with built in earthquake proof construction using new construction methods that are also environmentally friendly. After many years of continued use his Nayin inn has become a manifesto for the adaptation of Persian architecture for modern usage.