The song Kashmir closes side two of the double album Physical Graffiti. It is easily Led Zeppelin's greatest work. The orchestra playing the song's riff, the pummeling drums, and the grandiose lyrics definitely leave an impression on the listener which is not quickly forgotten.
The song was originally titled Driving to Kashmir and was basically about traveling through exotic lands. In particular, Morocco. The riff itself originated from a solo song by Jimmy Page called Swan Song.
On to the interpretation. The first verse was inspired by a long, straight stretch of road that cut through the desert. There was rock ridges on either side. The second verse is about the people who lived in these regions. Cultures that would have been so different than the western cultures that Zeppelin would have experienced.
The bridge section which goes "all I see turns to brown" is definitely a reference to the desert. It's baking sun, the endless sand (Sahara desert, anyone), and the almost total lack of life in the region.
The third verse conjures interesting imagery. The "pilot of the storm who leaves no trace" is probably a reference to Jimmy Page's obsession with the occult. Just change pilot to magus and you'll understand what I mean. Basically in this verse Plant is telling us that this land is like paradise or Shangri-la, if you like. He has every intention of returning.
The fourth and final verse is again about travel, but moreover about having the freedom to travel. Plant doesn't want any worldly possessions except the grace to be able to travel where he likes when he pleases.
The song ends with another bridge-type section. Much of this is improvised although the line that goes "let me take you there" is almost an invitation of the listener to travel to Kashmir and experience the culture and lifestyle there.
That's my interpretation of Kashmir. Personally I believe that the song was designed to be more poetic and have more imagery rather than to have a concrete meaning.
