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When Greenwich was chosen to be the Prime Meridian for sea maps in 1875, the main battle was between the British Empire who advocated for Greenwich and the French who pushed for Paris. While these two titans battled it out, most countries actually their own national prime meridian (16th Street from the White House for the United States) for local maps. However, when dealing with international/continental maps many Europeans used the Ferro Meridian. Ferro, another name for El Hierro island, is the western most of the Canaries Islands, the last bit of European conquered land before Columbus discovered the New World. As such it is the furthest western point of the Old World. Putting the meridian here would put all of Europe to the east and ensure geocoordinates would be written in the positive (with Greenwich places like Madrid are 3.4 degrees West which is written -3.4)
However, the imperial sea might of the British was too powerful for Paris and Ferro supporters to overcome. Besides not being strong enough, Ferro users used the island as a historic precedent and no one pushed too hard for the island's continued use. The French eventually relented in hope that the British would agree to adopt the Metric system. That effort of metrication failed; it took reforms started in the 1960s to get the United Kingdom to use metric but the change over still is not fully complete.
Today the Ferro Meridian is nothing more than a geographic/historic footnote. There is a monument to the island's past near the western shore which is a tourist attraction for those who journey to the Old World's edge.