There is no idol in Masjid Al-Haram (the Grand mosque) in Mecca. You may mean the building that is surrounded by Al-Masjid Al-Haram, that is called Kaba. However, Kaba is not an idol. It is not for worship. It is holy building to turn around during Hajj or Omra while praying for God and requesting His forgiveness.
AlMasjid Alharam (the Grand Mosque) surrounding Kaaba
Almasjid Alaharm is located in Makkah (or Mecca) in Saudi Arabia. It surrounds Kaaba that is the holiest Islam site. refer to related question below.
It is the Grand Mosques (or AlMasjid Alharam) that Surrounds Kaaba in Mecca (or Makkah) in Saudi Arabia.
it is AlKaabah in Makkah (or Mecca) in Saudi Arabia. AlKaaba is surrounded by the Grand Mosque (or AlMasjid Alharam).
It called Kaba (or Kaaba) that is surrounded by AlMasjid Alharam (or the Grand Mosque)
The Qibla is in the direction of Kaaba that is surrounded by the Grand Mosque (or Almasjid Alharam) that is located in Makkah (or Mecca) in Saudi Arabia. So, its direction depends on where you are located.
Almasjid Alharam (or the Grand Mosque)
Islam has mosques (not temples); the most famous three of them are:The Grand Mosque (or AlMasjid AlHaram) that is surrounding Kaaba in Makkah (or Mecca) in Saudi ArabiaThe Prophet Mosque (or AlMasjid AlNabawi) in AlMadinah (or Medina) in Saudi Arabia.AlAqsa Mosque (or AlMasjid AlAqsa) in East Jerusalem in the Palestinian Territories.
The holiest city for faith of Islam is Makkah (or Mecca) in Saudi Arabia. The Grand mosque (or AlMasjid AlHaram) is located in Makkah. This mosque surrounds the Kaba which is the oldest God house on earth.
You have to face the wall because you need to face the ka'bah _______________________________________________________ It is not true that you have to face a wall when a Muslim is praying. During praying, you; as Muslim; should face the direction of Kaba (or AlMasjid AlHaram) in Makkah (or Mecca) in Saudi Arabia.
Mecca (or Makkah) in Saudi Arabia (having Kaba surrounded by the Grand Mosque or AlMasjid Alharam)Medina (or AlMadinah) in Saudi Arabia (having AlMasjis Alnabawy or the Prophet Mosque)East of Jerusalem in the Palestinian Territory (having AlAqsa Mosque)
Mecca followed by Medina (both in Saudi Arabi) followed by AlQods (Jerusalem) are the three Islamic holy cities for having respectively the three mosques: Almasjid Al-Haram, Almasjid Alnabawy, and Almasjid Alaqsa.