A Renaissance landscape acquired by a Swiss collector’s father in 1957 vanished from public view for nearly 70 years; experts have identified it as a rare Altdorfer worth up to £5 million

• 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 identific