I had no idea I'd be lunching at one of the most famous places in the city. http://www.lapolar.com.mx/index1.html
So, the relatives brought us there on the drive back from the pyramids.
If you like or love birria, go. If you don't like birria, or are a vegetarian, do not go. It is a classic case of "if you do something right (in this case, for approximately 70 years), don't F with your success, don't try and add things to your menu, and don't try and cater to everyone who walks through the door.
There is a choice of birria (large bowl, with as many caldo refills as you might want), or tacos de birria. A plate of avocado is extra. Hot tortillas keep coming for the asking.
Loud (and competent) mariachis roam about. It is hard to carry a conversation in the place. The steaming bowl of birria comes a few minutes after you order it, because it isn't as if they're going to get your order confused with that of another birria order. There is an ample selection of beer and spirits. Wines are lacking and there's nothing by the glass.
A large (well, that is the only size because different sizes would complicate things) is approx. $120. The place is spotless, including the baño. Quick and easy valet parking ($30).
Tasty? Si. The best meal ever? No. Would I return? Si. A classic place.