6. TIME Life Building

Before leaving its eponymous midtown office building for new digs in lower Manhattan in 2015, TIME cleared out everything, including a copper time capsule sealed in the building’s 800 pound cornerstone. The capsule had been sealed in the building for the 55 years TIME had occupied it. While most cornerstone capsules don’t have a set opening date, the TIME capsule is scheduled to be opened in 2023, on the company’s 100th birthday.

At that time the original items will be replaced or supplemented by contemporary objects and the capsule re-opened in 2123. The capsule, which was sealed on June 23,1959, contains thirty pounds of documents including two LIFE books, other Time Inc. publications, microfilm information about Rockefeller Center, and a red pencil, the type preferred by original TIME editors.