Mansfield Town Football Club Open Day, 14/07/2013. Field Mill stadium, League Two. Two security guards holding the Conference National trophy at Field Mill stadium during an open day held for Mansfield Town supporters. Mansfield Town achieved promotion back to England's Football League by winning the Conference National in season 2012-13. Field Mill was the oldest ground in the Football League, hosting football since 1861 although some reports date it back as far as 1850, with Mansfield Town having played there since 1919. Photo by Colin McPherson.