‘Lost’ Inca city, picture above. Amazingly scenic and well and mysterious old city built by the Incas on a hilltop surrounded by virgin mountains. Best: April-June, September-November. OK July, August. (winter). Avoid: December-March (rain).
An ancient and ruined city in the middle of dusty, Syrian nowhere. Best: March-May, September-November. Avoid any season at present unless you are a jihadist. There is little of Palmyra is still standing due to crazed ISIS/ISIL fanatics.
Persepolis is packed with tombs, palaces, sculptures and friezes in a beautiful location near Shiraz while Isfahan contains an ebullient scattering of colourful architecture. Best: April-June, September, October. Avoid: winter.