Sack of the Second Temple depicted on the inside wall of the Arch of Titus in Rome, one of the many artifacts testifying to the existence of the Temple
Temple denial is the act of denying that the Jewish Temple on Mount Moriah, the Temple Mount, in Jerusalem ever existed.
Some radical Muslims deny that there were ever Jewish First or Second Temples in Israel at all and that Jerusalem was a Muslim city for thousands of years. However, there are several flaws with this theory, many Temple artifacts dating from 586 BCE have been found and the Western Wall, dating from the time of the Second Temple, still stands. Another problem is that Muslims only conquered Jerusalem in 638 CE, centuries after the Jewish Temple's destruction. Despite the fact that there is little evidence to actually prove the Temple never existed, some radical Muslims cling to this theory, hoping to prevent the Temple from being rebuilt.
A few Jews claim that Temple denial is even worse than Holocaust denial.