a) See: The face on Mars
c) See: Chesley Bonestell's "Stone Architecture on Mars, Demonstrating Mar's Two-Thirds Less Gravity Than Earths." huntdown"?
d) Curiosities to do with Schiaparelli's map of Mars
d.i) See: Map of Mars (compiled 1877-1886) Giovanni Schiaparelli Connects with one of the sides of the Kodiak Butte in Jezero crater on Mars?