Guanajuato is a city of incredible charm, as is almost immediately obvious on entering it by way of its subterranean main street.
The street follows the original course of the Guanajuato River, running beneath the city for almost 3 kilometers.
The river used to flood the downtown area with alarming frequency until a dam was built in the 1960's to contain it.
To navigate the city, you have to go on foot.
It's criss-crossed by hundreds of callejones (alleyways), the most famous of which is, undoubtedly, Callejón del Beso (Alley of the Kiss).
The local romantic legend has it that this callejón is so narrow that lovers, each standing on a balcony of either side of the alley, can reach across the alley and exchange a kiss!
The alleyway also is part of the route of the popular traditional callejoneadas of Guanajuato when student choral groups stroll the alleyways of Guanajuato at night, strumming their guitars and serenading the local populace.