How many people visit the Prado Museum each year?

How to get close to this number

Anchor on the world leader and scale down. The most visited museum in the world gets close to nine million a year, and a major national museum in a smaller capital gets a third to a half of that. A few million is the right band.

Throughput is the constraint here as it is for the Eiffel Tower question on this site. A museum can only admit as many people as its galleries can hold comfortably, and beyond a certain density the experience degrades to the point where visitors stop coming. Attendance records are capacity records.

The collection detail is the one that reframes what a museum is: roughly eight thousand paintings held and about seventeen hundred on display. Most of what a great museum owns is in storage permanently, which means the public institution is the visible fraction of a much larger archive — and curatorial choice determines what a national canon looks like.