intriguing vs challenging

intriguing and challenging both are adjectives.

Word	Noun	Adjective	Verb	Adverb
intriguing	No	Yes	No	No
challenging	No	Yes	No	No

As adjectives, intriguing and challenging are synonyms defined as:

intriguing (adjective)	challenging (adjective)
capable of arousing interest or curiosity	requiring full use of your abilities or resources
disturbingly provocative	disturbingly provocative
	stimulating interest or thought