Mexico City is truly one of the most amazing cities in the world with a mixture of both the old and new world. From the moment your plane starts to land in this vast city, you know that your trip will be quite an adventure. Once in your taxi and the moment you leave the airport, you are amazed at the large amount of slow traffic. The volume of the traffic can be stressful to some. The "Paseo de la Reforma  ", running southwest across the city, is one of the major tourist and business areas in Mexico City with many high quality hotels only walking distance from great restaurants and other tourist attractions. The only problem you will have is trying to see all of these sites during your vacation time. One of the most popular attractions in this area is the National Museum of Anthropology along the northwest part of the street. There are thousands of artifacts on display showing the history of the area and numerous items found from the many Aztec sites in the area. Walking southwest from the museum, you will soon reach the Mexico City Zoo, which is a great place to spend an afternoon. Across the street from the museum is the Chapultepec Castle, once an important site in the Mexican-American war. It's also a good idea to take the train up the hill to where the castle is located as the hill is steep  . It's important to keep in mind that Mexico City is over 7,000 feet above sea level and some feel it difficult to breathe when walking. You can take a taxi to the Coyoacan market during the evening on a weekend. It's a great place to get some cheap souvenirs to bring back home and to enjoy some traditional Mexican cuisine. However, you must be careful where you eat and that the meat is well cooked. The tourists in Mexico City may not be satisfied with  _  .
the high speed of the traffic the heavy traffic of the city the polluted air in the city their safety in the city