ISTANBUL - When Can and Sevda Elgiz opened the first museum for contemporary art in Turkey in 2001, they began a revolution in this country that continues to this day. Friends began to echo them, collecting art both local and international art, and a few, like the Elgizes, began to share those private collections with a wider public.

Of these, two extraordinary collections particularly stand out, remarkable for their breadth as much as for their quality: the corporate collections of Borusan Holding and of Abdi Ibrahim, both housed in spectacular buildings worth a visit in their own right. But because the collections are only occasionally open to the general public, they remain among Istanbul’s best-kept secrets, available just to a few privileged insiders.

This is especially true of the Abdi Ibrahim collection, stunningly exhibited in the pharmaceutical giant’s headquarters, a soaring tower designed by Italian architect Dante Benini. VIP guests to Contemporary Istanbul had exclusive access to the tower during the fair. Carefully curated by Abdi Ibrahim, chairman (and grandson of the founder), Nazih Barut and his wife, the collection fills the corners and corridors of offices, stairways and even the corporate cafeterias. Flooded with sunlight and glimmering with glass, the tower, despite being designed for offices, in fact provides an ideal museum setting for paintings and sculpture by Alex Katz, Burhan Dogancay, Shirin Neshat and Stephan Balkenhol.

Works by Shirin Neshat and Evan Penny hang in the collection of Abdi Ibrahim.

But, while visiting the Abdi Ibrahim tower requires a private invitation, Borusan Contemporary, a museum-within-a corporation housed in a so-called “haunted mansion” overlooking the Bosporus, is open to the public on weekends. Here, interactive, often science- and tech-based installations are a particular emphasis, though the permanent collection also includes more conventional works by Jim Dine, Bedri Beykam, and Devrim Erbil. More typical, however, are the kinds of projects on view in the current exhibition of works by Rafael Lozano-Hemmer. The artist transforms viewers into artworks, inviting them to breathe, look, or touch: for instance, visitors are asked to speak into a microphone and their voice then echoes for several minutes around an empty room, while lights track the frequency of the sound. In another, viewers face their own image as plumes of black smoke appear to pour from their eyes – “your evil thoughts,” one collector friend whispered as I watched the blackness from my eyes fill the screen, and I almost even believed her. They are challenging, seductive works, unusual for any museum to host, least of all, a privately funded one.

The fact that these institutions and others like them are entirely a private endeavor, not only speaks volumes about the politics of art in Turkey, but also says much for the inspiring devotion and dedication of collectors in this country, and the example that they set.