Whirlwind tour takes in numerous historical sites April 07, 1999 Share 1 -- MEXICO CITY -- As I climbed aboard the TWA flight, I wondered why I was going to Mexico City. But now I'm back, and I wonder no more. In the one day we were there, I found plenty of reasons that a vacation to Mexico City is not crazy, including a convenient three-hour flight from St. Louis.To be sure, there are negatives. It is disconcerting, for example, to see a beautifully preserved, centuries-old building next to a half-constructed, abandoned parking ramp or a glitzy hotel next to an empty slum building.Also, I think language can be a problem. Although I studied Spanish, I can understand it only in a language lab, with someone speaking very slowly into my headphones. And a tour guide at Dolores Olmedo Patino Museum spoke English only haltingly.That notwithstanding, the city's history is intoxicating, with attractions such as the Metropolitan Cathedral, begun in 1572 and completed more than 200 years later; Templo Mayor, which contains the main pyramid of the Aztec city of Tenochtitlan; the 17th century National Palace, and the murals of San Ildefonso College.During the day, we spent more time than needed with the Diego Rivera collection at the Dolores Olmedo Patino Museum. There also was a trip through the canals of the floating gardens of Xochimilco and an unguided tour and walk in Xochimilco's ecological park.Before we left the city, we were given folders brimming with pamphlets explaining much of what we'd seen during our brief visit. Looking these over, I know I'll be going back.