It is a surprisingly beautiful, decidedly underrated, state!
The lakes are gorgeous and there are many of them - I loved Lake Minnetonka during my brief stay in Minnesota.
A warning, since this is a fair review, however: Minnesota is a state of extremes. Though it has plenty of lakes, it's a land-locked state and, true to form, fluctuates between temperature extremes. You might get some nice weather, if you're lucky, but you could also face highs in the 100s in the summer and lows in the negative numbers in the winter.
Definitely pack accordingly and be prepared for the worst!
And the best, as far as beauty goes. Minnesota is not all cornfields. There are lots of beautiful forests and parks, including the one where I got the shot of the stunning waterfall above! It's a really beautiful state.
There are also some places along the rivers (see the Minnesota River above, where it meets with the Mississippi River - it's actually a tributary river of the Mississippi!) where there are sand "beaches."
Where does the sand come from in a land-locked state, you ask?