The Moscow Kremlin is a fortified complex in the center of the city made up of more than 15 buildings, 20 towers, and more than 1.5 miles of walls that are up to 21 feet thick. It's the official residence of President Vladimir Putin, although he doesn't actually live there.

While there are actually many kremlins throughout Russia, Moscow's is, by far, the most famous.

On a recent trip to Russia, I paid $10.50 for a ticket to visit a section of the Kremlin. Here's what it looks like inside.