Are translations of the book of Mormon into other languages made from English, or are the golden plates stashed in a temple somewhere?

I was poking around the Internet to see if there are any LDS-sanctioned modern translations of the Book of Mormon in English, and it seems there are not. (Although there's an unofficial one, *A Plain English Reference to the Book of Mormon* by Timothy B. Wilson.) However from another question on here I saw that the book of Mormon is still being translated into foreign languages. My question is, how is that the case? It was my understanding that Mormons say Joseph Smith returned the golden plates to the angel, so how are new translations made? From the English? And if foreign translations can be made from the English, why not a NIV-style English translation from the English?