When you examine the map of Lake Tahoe's 72-mile perimeter, you begin to realize the time that is needed to fully explore this mountain wonderland. And when you add in neighboring attractions, such as the vintage logging and railroad town of Truckee, you'll need to plan on a couple of days, at least, to hit the highlights. The Tahoe basin is a delightful collection of historical mansions, museums, aerial trams and parks, and every community along the shoreline has its unique charms. Some of them are not obvious, or not well marked. The following outline is designed to cover not only the"must-sees" for first-time visitors, but also some lesser-known points of interest for returning Tahoe regulars.