Spooner's historicals like to eschew historical fact in favour of the story, but then, to that point, let's just remember that the closest historical connection to Tegana in Marco Polo was in fact some 500 miles away during the events of the time in real life!
Spooner moved to Doctor Who from involvement in Gerry Anderson's Zoom Fish (hi Rob and Charlie!), writing a dozen episodes for the stingray adventures. He was also writer for Girl on the Trapeze, one of the only surviving episodes from the first series of The Avengers, and went on to create Randall and Hopkirk (Deceased), remaining in high demand until his death in 1986, from a heart attack.
Anyhow, the TARDIS landed on a cliff, and fell down. Not to worry, the Doctor thinks that can get fixed later, and the TARDIS crew are found lazing around a Roman villa.