Since few areas within the city of Venice afford high perspectives of the entire city, take the elevator (no stairs) to the top of San Marco's Campanile in Piazza San Marco. You may have to put up with a few elbows to get a spot against the railing, but it is all worth it for the spectacular panoramic views of Venice and the lagoon. While here, contemplate the history of this spectacular bell tower and observe the view from the same spot where numerous doges have stood, as well as Galileo. It was here that he introduced his telescope to the doge!
While it may not be the most original idea in the world, scaling the Campanile San Marco is no less breathtaking for it. It's a visually stunning way to orient yourself when you first arrive—though getting lost in Venice is often thought of as the best way to explore. (Don't worry, you won't be able to memorize all the little canals and winding alleys as you gaze out over the city skyline.)