Final answer:
10050 Cielo Drive has significant historical value as the site of the Manson Family murders in 1969. It's known for its association with this dark chapter in American history, not for numeric properties.
Step-by-step explanation:
The reason 10050 Cielo Drive is significant is that it carries a great deal of historical value. This address was the site of the infamous Manson Family murders which took place on August 9, 1969.
The reason this address is well-known is not due to it being a prime number, having a sum of digits totaling 15, or being a palindrome, but because of the tragic event associated with it, which resulted in the deaths of actress Sharon Tate and several others.
This event shocked the nation and had a profound impact on American culture and the perception of safety in society at that time.