To hell - To hades. See this explained, Matthew 11:23 (note).

And thou Capernaum, which art exalted to heaven,.... Referring either to the situation of it, which was on a very high hill; or to its privileges, through the ministry and miracles of Christ; or the phrase may be expressive of the pride and loftiness of the inhabitants of it, who were elated with the mercies they enjoyed, it being a most delightful, pleasant, and comfortable place to live in, as its name signifies. It was a famous port, commodiously situated by the sea of Tiberias; and, as Josephus (f) says, was in an excellent temperament of the air, and watered with a most choice fountain, called by the same name.
Shalt be thrust down into hell; meaning either the low condition to which it was to be, and has been reduced in a temporal sense, and continues in to this day; there being nothing of it now remaining, as travellers, who have been eyewitnesses of it, say (g), but a few little houses and cottages; or else the sad and miserable condition of the inhabitants of it hereafter: and so it is, that such who have lived in great plenty and pleasure in this life, and have thought themselves to be the favourites of heaven, and that they should enter there, shall be thrust down to hell by the arm of vengeance, with the utmost indignation in God, and shame to themselves: it follows in Matthew, "for if the mighty works which have been done in thee, had been done in Sodom, it would have remained until this day; but I say unto you, it shall be more tolerable for the land of Sodom, in the day of judgment, than for thee".
(f) De Bello Jude. l. 3. c. 35. (g) Vid. L'Empereur, Not. in Benj. Itinerar. p. 68.