What is in the Ka'bah? Some say there are idols in it. Is this true?

All perfect praise be to Allaah, The Lord of the Worlds.  I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

The polytheists used to set up idols around the Ka'bah, and used to hang pictures inside it. When the Prophet entered Makkah in the Year of Conquest there were three hundred and sixty idols around the Ka’bah. He started pointing to the idols with a stick he had in his hand and reciting: "Truth (Islam) has come and Falsehood (disbelief) has vanished." [Al-Bukhari and Muslim] The Prophet refused to enter the Ka'bah with idols in it; he ordered them to be taken out. The people took out the pictures of Ibraaheem (Abraham) and Ismaa'eel (Ishmael) holding "Azlaam" (divination arrows) in their hands. Thereupon, the Prophet said: "May Allaah destroy these people (Qaatalahumullah)! By Allaah, both Ibraheem and Isma'eel never played games of chance with Azlaam."

Then he entered the Ka'bah and said Takbeer ("Allaah is most great") in its corners. [Al-Bukhari] In another narration (also from Al-Bukhari), the Prophet did not enter the Ka'bah when he saw the pictures. Then he ordered the people to erase them, so they did. From that time, the area in and around the Ka'bah has been free from idols, all praise is for Allaah The Almighty.

Allaah Knows best.