Any visit to the capital of Ecuador would not be complete without a visit to the equator, just north of Quito. The Ecuadorian government has build a tourist monument called the "Mitad del Mundo" at the equator to commemorate the French and Spanish scientific expedition that measured the equator's location between 1736 and 1744. At this monument there is a yellow line painted on the ground to indicate the equator and one of the favourite tourist activities is to straddle the yellow line and think of yourself with one foot on each of the northern and southern hemispheres. Most people also visit the museum and leave with the satisfaction of standing on the equator.
But wait, pull out that handy-dandy GPS unit of yours and place it on the yellow line just to verify the accuracy of the line and you'll note that your GPS is definitely NOT on the equator -- what gives? When the French-Spanish survey was completed in 1744, the place where the yellow line sits today is where the equator was, but due to annual planetary variations the equator is now located north of the yellow line.
Onto the virtual cache: To qualify a find for this cache, you'll need to do two things: First take a picture of your GPS on the yellow line with the coordinates showing or a picture of yourself holding your GPS infront of the obelisk with the yellow line clearly present and upload it with your find. Second to satisfy yourself, find the location of the REAL equator and draw your own line on the ground and either place your GPS ontop of that line or stand on the line and hold your GPS and take a picture showing 0° latitude and upload it with your find as well.
Bonus question: how many metres or feet is the real equator from the yellow line?