Go on a road trip.
Take a look at the map and set out for an unknown town in the next state over. Make a special playlist and have a destination in mind, but the fun should be the journey.
Stop for quirky shops, take pictures of the scenery, and just enjoy the day. Don't forget to buy your Valentine a special keepsake along the way! A good gift to go with this date would be an old-fashioned road atlas that you can mark up over the years.