With nearly 30 towers and a partial restoration of the imposing 11m-high north wall, Belqays citadel is one of Iran's most visually impressive mud fortresses – at least, when viewed from certain directions. Once you're within the walls, there's relatively little to see, but the sheer quantity of scattered pottery shards, along with the eerie silence of the site, makes for a memorable experience.
Though now 5km from the city, this was once the heart of Ilkhanid-era Old Esfarayen, though it was abandoned after a 1719 onslaught by Afghans. Neighbouring fields are still dotted with archaeological sites and sitting all alone is the distinctive, domed mausoleum of 15th-century poet Sheikh Azari.
Taxis from Esfarayen cost IR100,000 to IR150,000, depending how long you stay.