San Diego Sightseeing Tour with Optional Harbor Cruise. See San Diego's key sights, such as Old Town and the Gaslamp Quarter, on this guided sightseeing tour aboard a comfortable coach. The leisurely pace allows time for walking around and snapping pictures, if you like. Consider upgrading to include a relaxing 1-hour San Diego Bay cruise. Book this San Diego Sightseeing Tour with Optional Harbor Cruise From $37.99.