The <a href="https://en.wikipedia.org/wiki/London_Underground" id="mwxw" rel="mw:WikiLink" title="London Underground">London Underground</a>'s <a href="https://en.wikipedia.org/wiki/Great_Northern,_Piccadilly_and_Brompton_Railway" id="mwyA" rel="mw:WikiLink" title="Great Northern, Piccadilly and Brompton Railway">Great Northern, Piccadilly and Brompton Railway</a> opens.