Travel Trivia: Where is the steepest-sloped street in the world?

C. Baldwin St., New Zealand

c.  Baldwin Street, New Zealand

C, New Zealand 

Waipi'o Valley Road, Hawaii. USA.

Having experienced the down and back up, plus the condition of the road, I'll attest to it. 

That said, it's worth it!

 C. New Zealand

c.  Baldwin Street, New Zealand

 C

C

C. 

 I'll guess C. Baldwin Street.