Jerusalem is considered the Holy Land for Judaism and Catholicism I believe. Mecca for Muslims. Varanasi/Haridwar for Hindus.
The Qur'an is the most sacred book of the Muslims.
Mecca is the most important pilgrimage in Islam.
Jerusalem. However, Jerusalem is a sacred city for also both Christians and Muslims.
No one specific color is ''sacred'', however the color most often associated with Muslims is green, because the Ottomans, who used it in their flag, were primarily Muslim.
The Qur'an is the most sacred book of the Muslims.
Makkah (or Mecca) in the Kingdom of Saudi Arabia
The most sacred text of the Muslims is the holy Qur'an, that is the word of Almighty Allah revealed to the last Prophet of Islam (SAW).The collections of the sayings of the holy Prophet (SAW) are also sacred books of the Muslims.
Mecca, in Saudi Arabia, is the most sacred city in Islam, to which millions of Muslims travel every year on Pilgrimage.
Muslims don't worship any building. Even, the Kaaba (that is the most sacred Islamic building) is not worshiped by Muslims but respected and honored by Muslims. If you wish to read about places where Muslims worship (both houses of worship and sacred sites) read the Related Question below.
God was not the author of the Bible, although some believe that the various authors may have been divinely inspired. Muslims do believe that God wrote the Koran, which is held in heaven, and that the angel Gabriel told the Prophet Muhammad what to write, so that he would have a copy on Earth. However, most scholars do not believe that the Koran really originated in this manner.
The Kaaba in Mecca became the principal object of worship among the Arabs. It is a sacred black stone structure that Muslims believe was built by Prophet Abraham and his son Ishmael. Muslims face the Kaaba when they pray and it is considered the most sacred site in Islam.