On September 29th, 1986, Iron Maiden released their sixth album, Somewhere in Time. Like many of their covers, the artwork was created by Derek Riggs, who snuck dozens of references to the band’s previous work and their lives in his art. Here are 32 hidden references made on the front and back covers of the album, which is now 37 years old.

FRONT COVER:

1. The street is named “Acacia,” much like the Number of the Beast track “22 Acacia Avenue.”

2. The poster shows Eddie from the band’s debut album with graffiti that reads “Eddie lives.” Torn posters also appear on the covers of the “Sanctuary” and “Women in Uniform” singles.

3. The Eye of Horus is in neon, a reference to the lyrics in the title track of Powerslave, which mentions the Egyptian symbol of protection.

4. The trashcan on the lamppost is just like the one on the Iron Maiden cover.

5. The black cat with a halo also appears on the back cover of Live After Death.

6. “Websters” is a reference to Charlie Webster, the art director for the band’s label, EMI.

7. The symbol on Eddie’s chest is Riggs’ artistic signature.

BACK COVER:

8. The clock reads 23:58, or, like the Maiden song of the same name, "2 Minutes to Midnight."

9. The opera house is called "Phantom Opera House." On their first album, Maiden has a song called "Phantom of the Opera."

10. Aces High Bar is a reference to the song "Aces High."

11. A Spitfire airplane is flying above the Aces High Bar. That same plane can be seen on the cover of the "Aces High" single.

12. "Sand Dune" references the Piece of Mind song "To Tame a Land," which is based on the novel,Dune.

13. The pyramids are reminiscent of the theme of the Powerslave cover.

14. The grim reaper seems to be the same one as the reaper on the Trooper and Live After Death covers.

15. The marquee at the movie theater says Life After Death, the name of Maiden's 1985 live album. It also saysBlade Runner, which inspired the cover art.

16. This sign, which reads "Ancient Mariner Seafood Restaurant," references the song "Rime of the Ancient Mariner" off Powerslave.

17. The Ruskin Arms is one of the first venues where Iron Maiden ever played.

18. The woman in a red-lit room is a nod to "Charlotte the Harlot," who is mentioned in some of the band's songs.

19. Rainbow is another venue where Maiden has played. They also recorded their first live video there. It came out on VHS in 1981.

20. L'Amours Beer Gardens references the Brooklyn rock venue L'Amours, where Maiden once performed.

21. This is no ordinary phone booth - it's the TARDIS from the BBC series Doctor Who. The cover of the "Wasted Years" single references the control panel in the TARDIS.

22. Icarus in flames falling from the sky is also on the cover for the band's 1983 single "Flight of Icarus."

23. The soccer score shown is "West Ham 7.....Arsenal 3." Bassist Steve Harris is a big fan of the West Ham United Football Club.

24. It's hard to make out this sign but it says "Tonight: Gypsy's Kiss." That was the name of Steve Harris's first band.

25. Long Beach Arena is the name of the venue where most of Live After Death was recorded.

26. Maggie's Revenge is a reference to British Prime Minister Margaret Thatcher, who can be seen on the covers of the "Sanctuary" and "Women in Uniform" singles.

27. This shape is the same as the bracket that holds Eddie's skull together on Piece of Mind and the albums after it.

28. The illustration of Bruce Dickinson is holding a brain, a reference to Piece of Mind.

29. Nicko McBrain is wearing aviator goggles because he had a pilot's license. He also wears a shirt that says "Iron What?"

30. Hammerjacks is the name of a Baltimore nightclub and concert hall the band went to.

31. Tehe's Bar is where the choir vocals in theSomewhere in Time song "Heaven Can Wait" were recorded.

32. The Herbert who ailed was author Frank Herbert, who wrote Dune. He died in 1986. It's also a reference to his unpleasant response to the band's request for permission to use "Dune" as the title for "To Tame a Land," which was inspired by the book.

Bonus: Can you find Batman?

Baby rhino playing in the mud right here at the San Diego Zoo Safari Park.