
Rhodes is a famous Greek island with great ruins, lovely scenery and nice coast.
Crete is a beautiful place to see the remnants of the ancient civilizations, e.g., even as old as 11000 years (https://greece.greekreporter.com/) – I probably shouldn’t call it as ancient neither civilization, anyway, the age is impressive!
The best known monasteries of Greece are the Meteora Monasteries.
These wonderfully located Greek Orthodox monasteries are one of the UNESCO World Heritage Sites.
First Monasteries of Meteora were built in the 14th century; in its peak, there were 24 monasteries. In a meantime, many of the monasteries were destroyed or bombed, and currently there 6 six active ones.