Does the lake of fire currently exist?

Was it already prepared, or will it be prepared, prior to the second advent?

When the fire and brimstone of this lake is first mentioned in the book of Revelation:

Revelation 14:10 The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb:

  11 And the smoke of their torment ascendeth up for ever and ever: and they have no rest day nor night, who worship the beast and his image, and whosoever receiveth the mark of his name.

It doesn't indicate that it already exists.

Obviously it exists by the time:

Revelation 19:20 And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone.

But does is it already prepared?

Matthew 25:41 Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels:

It is prepared, and it will be there when it is needed.

But was it prepared from the foundation of the world?

Or was it prepared after the devil first sinned?

Or was it prepared after Adam fell?

Or will it still be prepared, before it will be needed?