Photos: Second-Half Travels, CC BY-NC 2.0 DEEDThe Gran Hotel de la Ciudad de México is a rare and unique spectacle. The hotel survives from the Porfiriato period of the late 19th century and remains one of the City's oldest. It's today most popular for the terrace restaurant on the upper floors that allow exquisite views of the Zócalo and the entire area. The Centro Mercantil was opened by President Porfirio Diaz in 1899 offering mostly merchandise shipped from Europe. The stained glass ceiling is modeled on the Arte Nouveau works so prominent in the Paris of those years. One of the hotel's most striking features even today, it was the work of the French artist, Jacques Grüber and finished only in 1908. Remarkably, the Centro Mercantil continued operations until 1958. It then took some ten years for the Howard Johnson's company to retrofit the building to re-open as a hotel in time for the 1968 Olympic Games. That partly explains the hotel's often surprisingly affordable rates, too. Even today. It was remodeled again between 2003 and 2005. During that remodeling, the enterprise was renamed the Gran Hotel de la Ciudad de México. The total number of guest rooms was reduced at that time to the 60 that remain today. The same rehab also improved the rooftop terrace and restaurant that's one of the best ways to get to know the hotel. And with the views, it's also among the best places to take in the Zócalo, the National Palace and the Cathedral.