One of the most famous examples of this is

Walter de Maria’s The Lightning Field. Its exact location is a tightly-guarded secret – all that is known is that it’s in the high desert of western New Mexico, although small groups of visitors can book to be taken there. Another is the temporary land art of Martin Hill and Philippa Jones, such as Synergy – a piece that was installed in Lake Wanaka, New Zealand, in 2009.