"Inca Roads" is the opening track of the Frank Zappa and the Mothers of Invention 1975 album, One Size Fits All. The song features unusual time signatures, lyrics and vocals. The marimba-playing of Zappa's percussionist Ruth Underwood is featured prominently. The song was played in concert from 1970 to 1976, 1979 and 1988.

"Inca Roads" for the most part explores the stereotypes of aliens encountering the Incan civilization. These themes, like the album cover of One Size Fits All seem to parody the spirituality of many progressive rock albums around the same era. The lyrics "Did a vehicle come from somewhere out there, just to land in the Andes? Was it round and did it have a motor or was it something different?" imply that a UFO is landing in the Andes Mountains. As the song progresses, the lyrics become sillier and seem to mock the beginning of the song. An example of this is "...or did someone build a place or leave a space for Chester's thing to land (Chester's thing... on Ruth). Did a booger-bear come from somewhere out there..." The non-serious nature of these lyrics and even the music itself seem to be mocking other progressive rock bands and their possibly forced divine depth.

The song starts with dominant vocals, drums, and marimba, but soon features a guitar solo performed by Zappa in late September 1974 at a live performance in Helsinki, Finland. An edited version of this solo recording (and part of the bass and drums accompaniment) was "grafted" onto a performance of the song from August 27, 1974 at KCET in Los Angeles. This combination of performances forms the backbone of the album version from One Size Fits All. Later, George Duke plays an equally complex solo in 7/16

 In the video of the KCET performance, entitled A Token of His Extreme, Zappa is seen smiling gleefully as Duke plays his solo, as he plays the backup chords. After a short marimba solo, "Inca Roads" reprises its snappy intro. The song ends with the lyrics "On Ruth, on Ruth, that's Ruth!", acknowledging Underwood for her leading on the marimba.