The better known city beaches in the Twin Cities can be mighty fine spots to while away the day. If you like to people-watch, you can check out the weirdos at Hidden Beach at Cedar Lake, the hard bodies at Thomas Beach at Lake Calhoun, or the family picnickers at Lake Phalen. But if you want the cleanest water for swimming, you should take the 30-minute car ride to St. Croix. There are plenty of swimming spots and beaches here—some sanctioned, many not. But wherever you put down your towel, you'll find a sweet little getaway and all the elbow room you'll need to stretch out and relax.