Claim: Tremont Street Subway is a tunnel.
Evidence: The Tremont Street Subway in Boston 's MBTA Subway system is the oldest subway tunnel in North America and the third oldest worldwide to exclusively use electric traction -LRB- after the City and South London Railway in 1890 , and the Budapest Metro 's Line 1 in 1896 -RRB- , opening on September 1 , 1897.