Led Zeppelin - Houses of the Holy (LP, 1973)
Bit of a risqué one this at it features the bottom of a child, or rather of several children climbing up the rocks on Giant's Causeway. These frolicking infants were actually just two siblings, with the images super-imposed and played around with quite a bit by Hipgnosis before coming up with the final product. Wouldn't be allowed these days.
Read all about the album design here on wiki
Read about the now 42-year old album album here on ultimateclassicrock.com
