I don’t think there are any untranslated and readable large Latin texts now available.
There are, however, many small fragments in both Greek and Latin that have not been translated. There are, for example, many papyrus fragments found in an ancient Egypt rubbish heap at Oxyrhynchus that are waiting to be translated. Much of these are in Greek, however.
https://en.m.wikipedia.org/wiki/Oxyrhynchus_Papyri
There also are still hundreds of carbonized, unopened scrolls found at the Villa of Papyri at Herculaneum that was devastated by Vesuvius in 79 AD. These might all be in Greek, however. The examined scrolls have been Greek texts on the subject of Epicurean Philosophy.
https://en.m.wikipedia.org/wiki/Herculaneum_papyri
Of course, there will always be newly discovered statues and monuments that have previously-untranslated Latin inscriptions.