The Glyptotek houses more than 10,000 works of art divided up into two principal collections.

They are on display at the Soane museum, whose 9,000 Adam drawings make up one of its principal collections.

The Greek Church has two principal nomocanonical collections.

Its principal archival collection comprises records relating to some 140,000 charities.

The principal collections include species from China, Japan, and England.

It contains more than 3,500 plant species from all over the world, with principal collections as follows:

The principal collection of O'Neill papers is at Yale University.

The principal collection is presented in its original domestic context as a private collection.

Provided the public has free access to the principal collections on display, it does not matter that you occasionally charge people to see special exhibitions etc.

The National Roman Museum, with Rome's principal collection of ancient art, has been mostly closed for the same period.