This area will only be busy if there is an event taking place at Monumento a la Bandera, but always be on the lookout for muggles.
According to Wikipedia, the reason the giant flagpole is here is as follows:
“On 1 July 1999, (Mexican) President Zedillo officially started the flag program by issuing a decree that was published in the government register, Official Journal of the Federation. While the formation of the flag project was one aspect of the decree, the overall aims of the law were to promote the flag, the Coat of Arms, and the National Anthem to instill a sense of patriotism into the Mexican population”.
You do not have to go inside the gate to access the cache. In a desert always be on the lookout for for desert creatures, such as snakes, scorpions, wasps.