I'm referring to the 1864 novel :) What do you know, it has a TV Tropes page[0]. Journey to the Center of the Earth does seem to be the oldest thing on there,

I'm referring to the 1864 novel :) What do you know, it has a TV Tropes page[0]. Journey to the Center of the Earth does seem to be the oldest thing on there, after all - not that TV Tropes is necessarily comprehensive. [0] https://tvtropes.org/pmwiki/pmwiki.php/Main/SundialWaypoint https://tvtropes.org/pmwiki/pmwiki.php/Main/SundialWaypoint