I agree with KARL. Several years ago, I stayed in Reykjavik and then spent two weeks touring the north coast. The volcanic landscapes and features are unforgettable. You can visit active volcanoes, geothermal areas (geysers, mudpots etc) and swim in swimming pools of water heated by magma just below the surface. The Icelandic culture is very rich and the people are so warm and friendly. Iceland is the only country I have ever left with tears in my eyes.
From Iceland I flew to Angmagssalik in Greenland for a week and that was an add-on to the Iceland holiday. Greenland was the most beautiful place I have ever visited. There are no roads, no noise, and virtually no evidence of people. The valleys are so remote that when you go for a walk, your feet are probably the first to ever walk in certain areas. The beauty is quite breathtaking and something I will never forget. With regards to temperature, Iceland and Greenland are surprisingly warm in the summer. I went in August and was able to wear just a T-shirt for most of the time, although you need a sweater sometimes.
Hope that helps Scarlett but it depends on exactly what interests you. If you love culture and natural history you will love Iceland and Greenland.