A road trip! It's wonderful to just get in the car with some great music, drive and enjoy the scenery. Just make sure you go somewhere beautiful, and plan lots of fun stops along the way.
My favorite road trip (solo) was probably the Cotswolds of England.... lots of tiny, storybook villages to travel through, walk through, enjoy tea at, and all the cute shops, and it's very easy to get lost there, which makes it all the more fun in navigating. hehe A "detailed" map is a must! Driving on the left side of the road and all the round abouts just add to the fun.