Rare Altdorfer landscape hidden for 70 years after 1957 acquisition could fetch £5 million

A painting that remained in a private collection and out of public view for nearly seven decades is now attracting attention from the international art world. Created around 1520 by German Renaissance artist Albrecht Altdorfer, the small landscape depicts a densely wooded forest, a rainbow behind the trees and a distant castle beneath a cloudy sky.

The artwork was acquired by a Swiss collector's father in 1957 and remained out of public view until its recent identification as a rare work by the Renaissance master.The painting, titled A Thickly Wooded Landscape With a Rainbow Behind the Trees and a Distant Outcrop to the Right Beneath a Cloud-Laden Sky, will be offered at Sotheby's Old Masters Evening Sale in London on December 9, 2026. According to Sotheby's auction catalogue, the work carries an estimated value of £3 million to £5 million.