Complex sentence: Thereafter a visit to the entrance at least, seems to have been on every passing tourist's schedule, featuring, for example, in the 1853 edition of "Garnett's Craven Itinerary".
Split into simpler sentences: Thereafter a visit to the entrance at least, seems to have been on every passing tourist's schedule. It certainly featured in the 1853 edition of "Garnett's Craven Itinerary".