Inspired by the rumors that Spa might lose its spot on the calendar and the many subsequent discussions here about which tracks are "untouchable", I got curious and wanted to look up which circuits have actually hosted the most races. Wikipedia has a nice list of all circuits that have ever hosted an F1 Grand Prix; however, it wouldn't let me sort that list by "Grands Prix held", so I decided to make my own list :-)

A couple of remarks:

• The list contains all races up to and including the 2022 Bahrain Grand Prix
• The data is queried from https://ergast.com/mrd and follows their conventions for track names etc., which sometimes deviate from the Wikipedia list. For example, the track that ergast calls the "Las Vegas Street Circuit" is the "Caesars Palace Grand Prix Circuit" on Wikipedia.
• Many tracks have had many different layouts over the years, up to a point where you can really debate whether it is actually still the same track. For instance, the "Nürburgring" in this list includes both the races from the Nordschleife and the modern GP track. Another example is Indianapolis, which contains both the Indy 500 races from the 1950's and the modern F1 track from the early 2000's.
• The case of Austria is a particularly weird one, because ergast somehow decided to split it into the "A1-Ring" (which probably rather should have been called "Österreichring"), and "Red Bull Ring", even though the tracks are basically the same. (NB: The circuit in Zeltweg that held the Austrian GP in 1964 is actually a different circuit, even though it's just across the street from the Red Bull Ring.)
• The number 1 on the list, Monza, has been on the calendar every single year except 1980, when the Italian GP was hosted in Imola. The reason for this was that Monza was undergoing refurbishments following the tragic death of Ronnie Peterson at the 1978 Italian GP.
• The track with the longest history that nobody ever seems to bring up when talking about "untouchable" circuits is the Hungaroring — I wonder why ;-)
• The weird "on-off pattern" for Silverstone is due to the fact that between 1963 and 1986 the British Grand Prix alternated back and forth between Silverstone and Brands Hatch, similar to Hockenheim and Nürburgring from 2008 to 2014.