Ecuador has a monument on the equator, and Greenwich, UK has a line on the ground representing the prime meridian. Suppose a country on the arctic circle or the tropic of cancer proposes a monument on their respective significant latitude lines. How feasible is it?

If the tilt of the earth's axis (obliquity of the ecliptic) is changing at about 47 arc seconds per century, how far would the monuments have to move each year?