The light artist James Turrell has announced that he will allow an exclusive group of visitors to access the Roden Crater, a volcanic cinder cone that he acquired in 1977 and that he has been turning into an epic land art–work ever since, In Collect reports.

The 400,000-year-old extinct volcanic crater is located near Arizona’s Painted Desert, “an area where you feel geologic time,” and where “you have a strong feeling of standing on the surface of the planet,” according to Turrell.

His goal is to turn the inner cone of the crater into a naked eye observatory.

But the Roden Crater is a long and complex project and, as part of a fundraising effort, Turrell has decided to allow some visitors into the site, from May 14 to 17. But, make no mistake, this is no public affair. According to In Collect, only “serious patrons of the arts” who can pledge $5,000 towards the ambitious project will be considered.

Selected guests will also be required to spend an additional $1,500 towards an on-site dinner, a tour of the site, and accommodations. Turrell, moreover, has kept the numbers low: he will allow no more than 20 visitors per day, for four days.

The Roden Crater is not currently open to the public, and many in the art world are fired with expectation to see the land art masterpiece in the making. Yet, some recognized supporters of the project—those who have helped finance the construction and those who have commissioned works by Turrell—have already been welcomed to the monumental site.