Sounds fascinating...

HISTORY CHANNEL - Monday, Dec 22nd @ 9:00 pm ET

Cities Of The Underworld : Secret Holy Land
Airs on Monday December 22 09:00 PM

E Country is home to some of the oldest settlements in the world. This cradle of mankind is a country born from legend and shrouded in mystery. An ancient home to both Jews and Muslims, E Country is also the world's second oldest Christian nation. But if you were a Christian during ancient times, and if you wanted to stay alive, the only place to practice your faith was underground. From underground engineering marvels to remote, cliff-hanging caves, E Country's isolated churches allowed Christianity to evolve in ways found nowhere else in the world. From tombs of banished emperors and subterranean cathedrals where orthodox priests have been worshipping for thousands of years, to the buried Palace of the Queen of Sheba
and the possible resting place of the Ark of the Covenant, clues to E Country's lost legends and tribes are littered right here...in the African underground.