Should "the" or "el" appear before a Spanish proper noun placed in an English text

I have a textbook that refers to the Spanish royal road that linked Mexico City and Santa Fe as "El Camino Real", though the full name in Spanish is "El Camino Real de Tierra Adentro" to distinguish is from multiple other royal roads in the New World. This reference uses "El" everywhere instead of "The". There are English translations of the word, but I want to be precise and avoid confusion, so in my writing use the Spanish name, but I'm writing in English everywhere else. So I want to know which is correct to use:

1. El Camino Real de Tierra Adentro was a trade route that linked Mexico City and Santa Fe. Bob was a trader who sold his goods on El Camino Real de Tierra Adentro.

OR

1. The Camino Real de Tierra Adentro was a trade route that linked Mexico City and Santa Fe. Bob was a trader who sold his goods on the Camino Real de Tierra Adentro.

Can I equally use them both, or is one more correct?

Solution 1:

The formal name in English of what used to be the main road from San Francisco to San Jose is El Camino Real (this is what you see on the street signs).

In addition, we very rarely put the in front of street names in English. You wouldn't say that the prime minister lives on the Downing Street. There are some streets which include the in their formal names (e.g. The Pennsylvania Turnpike), but they're rare. So saying The Camino Real is a strange mixture of Spanish and English, where you've translated El rather than dropping it, as would usually be done in English.

So I would recommend using El.

This doesn't necessarily apply to things other than street names ... in San Francisco, it's The Presidio rather than El Presidio.