1. Centro Historico, also known as the Historic Center of Mexico City, is located in the heart of Mexico City and is considered the cultural and historical center of the city. It covers an area of approximately 668 blocks and is home to more than 1,400 significant buildings, including ancient Aztec ruins, colonial-era churches, and modern buildings. The main attraction of Centro Historico is the Zocalo, which is the largest public square in Latin America. It is also home to several museums, art galleries, theaters, and restaurants.

2. The working hours of different attractions in Centro Historico may vary. However, the Zocalo and many of the restaurants and shops are open from early morning until late at night. The phone number for Centro Historico information is +52 55 5522 9937.

3. Most parts of Centro Historico are accessible by foot. However, there is also a Metro line that runs through the area, making it easy to get around. Admission to attractions in the area may vary, but many are free to enter. It is recommended to check the individual attraction websites for information on admission and ticketing.