The engraved Chinese characters in the picture mean "the most respectful (or honorable) mountain." In ancient times, Chinese emperors would normally go to Tai mountain and pray to God. Consequently, the mountain was honored as well. The direct translation of the four characters should be "the most respectful one among the five tallest mountains." The "five tallest mountains" are Tai, Heng (north), Heng (south), Hua and Song. Of course the Chinese had not discovered the Himalyas at that time. (Thanks to Xia (Sam) Zhang for this explanation.)