North Beach is Burlington's easiest proper beach, a sandy stretch on Lake Champlain north of the busier downtown waterfront. In summer it is where locals come for swimming, picnics, volleyball, and long lazy views toward the Adirondacks.
It is more relaxed than the central waterfront and works well by bike, especially if you are following the Burlington Greenway. The water is at its best in high summer; outside that season, come for the lake air and sunset rather than a swim.