Where is Mecca and what's the Kabba and Hajj?

Question:
Where is Mecca and what's the Kabba and Hajj?

Answer:
Mecca is the capital city of Saudi Arabia's Makkah province, in the historic Hijaz region. It has a population of 1,294,167 (2004 census). The city is located 73 kilometers (45 mi) inland from Jeddah, in the narrow sandy Valley of Abraham, 277 meters (909 ft) above sea level. It is located 80 kilometers (50 mi) from the Red Sea.
The city is revered as the holiest site of Islam, and a hajj pilgrimage is required of all able-bodied Muslims who can afford to go, at least once in their lifetime.
The Hajj: In Arabic, the word, Hajj means a resolve of magnificent duty. Hajj also means visit to the revered place, or the pilgrimage to the Ka’bah in the Grand Mosque (Masjid AlHaram or Haram AlSharef), in the City of Makkah (Mecca), in Arabia, which is one of the basic manifestations of the Islamic faith, and a display of unity of the Muslims throughout the world.
The Kabba: (The Sacred House), is a building located inside the mosque known as Masjid al Haram in Mecca. The mosque was built around the original Kaaba.
The Kaaba is the holiest place in Islam. The qibla, the direction Muslims face during prayer, is the direction from any point to the Kaaba.

Refrence:

Ref: www.sibtayn.com