Albuquerque, the state's largest city, is the hub of the state. Each October, city skies are full of imperial reds, bold blues, and vibrant yellows. The event is the world-famous Albuquerque International Balloon Fiesta, the largest hot-air balloon event in the world. Sandia Peak Tramway, the world's longest tramway, runs 2.7 miles to the 10,300-foot summit. Owned and operated by the 19 Indian Pueblos of New Mexico, the Indian Pueblo Cultural Center focuses on the history of traditional Pueblo culture. Streets around the central plaza of Old Town are lined with 300-year-old adobes and contain assorted artwork, jewelry, and specialty shops. Petroglyph National Monument on the West Mesa contains up to 15,000 ancient rock carvings created around 1300 A.D.