Hi, my family (including kids ages 20, 16, 7) are visiting London for 5 nights. We want to see some of the countryside, and think Dover would be an interesting place. Since we'd be so close to the Channel, wondering if it would be worth taking a trip through the chunnel just to cross it off our list. Would that be a worthwhile thing to do, or does it take too long to make the trip? We could spend the night in either Dover or on the other side. Thanks!