The river that flows through Oslo.
I think it's pretty cool that a capital has a river as big as this one, that flows through the city. I spent two days here, and it poured rain most of the time. I love it, it makes for the best photos. The city is also a very cool place. So much happening, while still being relatively small.
If you ever get the chance to visit, you should do it. I highly recommend this place!