(1) the underground ::
il sotterraneo(2) underground station ::
stazione della metropolitana(3) underground train ::
metropolitana(4) underground water ::
acqua sotterranea(5) underground railway ::
ferrovia metropolitana(6) by underground ::
in metropolitana(7) go underground ::
andare sottoterra(8) underground economy ::
economia sommersa(9) underground passage ::
passaggio sotterraneo(10) underground river ::
fiume sotterraneo