Take a day-drive North on Hwy 1 toward Carmel.  You'll enounter 2 lighthouses, high-altitude cliffs, lookout stops everywhere, bridges, and stunning scenery at every bend.  The drive only takes like 2 hours, and you can spend the afternoon in the Carmel/Monterey area (maybe Cannery Row?), and head back in the evening as the sun begins to set.  There is no gas available along this drive, so fill up before you head out, and fill up before you return... just in case.