Fill in the gaps with the words derived from the words given

This summer may become a [ ] opportunity to travel around Russia. In three months you can see a lot of [ ] places and [ ] sights. Probably, the first cities that you should visit are Moscow and Saint Petersburg. These are the two biggest cities, and they have some nice tourist [ ].Then, you could go to the [ ] part of Russia, the Caucasus. The mountains will take your breath away, that's for sure! And then I can really recommend you travelling through Siberia—it's a fantastic place that is worth a visit!