[Geordieprincess]

As others have said Lindos and up to the acropolis, although it’s a stinky walk from all the donkey poo. And very hot in Aug, take plenty of water.
Rhodes town is also very nice, the Grand masters palace is worth a visit and an evening meal overlooking the old town square was lovely.
Kalithea springs was quite nice but you either need water shoes or be happy to enter the sea into deep water as it’s very uncomfortable underfoot.
Have a great time.