One place to visit in the isle of Rhodes is the Temple of Athena located in Lindos, which is the warmest place in the whole Greece so make sure to take some water with you. The temple itself is located on top of a hill and in order to get there you have to climb quite a many stairs under a boiling hot sun, or if you're not one of the most athletic types you can ride a donkey up to the temple.
The temple dates back to 300 BC and has been build over the ruins of an even older temple. I got a pretty nice shot of those old pillars and had a great time exploring even though the temperature was way over 30 degrees celsius.
The view is great and that is one of the big revards you get after climbing all the way up. The Mediterranean Sea look very beautiful and you can really see the beauty of the island from above.