Stevie Nicks performed the lead vocals on this song, which was written by Sandy Stewart with contributed lyrics by Stevie Nicks. While listening to the demo by Stewart (who did not provide any written lyrics), Nicks misunderstood the phrase "All the way down you held the line" as "All the way down to Emmeline", which is what she sang. Nicks also added an ambiguous word, sounding like "Sara" or "Tara", during the breaks between choruses and verses. (The word may refer to Nicks' song "Sara", on Fleetwood Mac's 1979 album Tusk, or even to another Nicks composition on Tango in the Night, "Welcome to the Room... Sara"; the lyrics to the latter song include references to Scarlett O'Hara and Tara, and Nicks has used the name "Sara" several times in the past as a pseudonym for herself.) Some fans have also speculated that she may be saying "Aaron" rather than "Sara" or "Tara." The title of the demo by Sandy Stewart was reportedly called "Aaron." These additions as well as various other changes to the lyrics, led to Nicks' credit as co-writer of the song.
The song was also released as a 12-inch single, which included an extended remix, a dub mix, and an instrumental, "Book of Miracles", which later became the track "Juliet" on Nicks' 1989 album The Other Side of the Mirror. A limited edition 12-inch picture disc version was also released in the UK.
In 2009, Pictureplane sampled "Seven Wonders" in the song "Goth Star" from the album Dark Rift. In 2013, Classixx sampled "Seven Wonders" in the song "Hanging Gardens" from the album of the same name. "The Seven Wonders", the season finale of American Horror Story: Coven, opened with Nicks performing the song. This helped the song to reach #18 on the Billboard 'Digital Rock Songs' chart with sales of 13,000.