No, there is no evidence of any gate by that name or description existing. The text means just what it appears to mean: that it is impossible for a rich man to enter the kingdom of God. Naturally, this is unacceptable to many Christians, so various creative interpretations have been invented over the centuries. The myth about the gate dates back to the 9th century (source: Mark (Smyth & Helwys commentary). A similar turn of phrase about an elephant passing through the eye of a needle is known from rabbinical literature.