This is what we found on Wikipedia regarding the Sky Views Observatory with Free Glass Slide:

The John Hancock Tower, colloquially known as the Hancock, is a 60-story, 790-foot (240 m) skyscraper in the Back Bay neighborhood of downtown Boston, Massachusetts. The pinnacle height (including antennas) is 852 feet (260 m). Designed by Henry N. Cobb of the firm I. M. Pei & Partners, it was completed in 1976, and has held the title as the tallest building in New England ever since. In 2015, the lease belonging to the John Hancock Mutual Life Insurance Company, for which the skyscraper was named, expired, and it was renamed to its address at 200 Clarendon Street.

The building is widely known for its prominent structural flaws, including an analysis that the entire building could overturn under certain wind loads and a prominent design failure of its signature blue windows, which allowed any of the 500-pound (230 kg) window panes to detach and fall, up to the full height of the building, endangering pedestrians below.

The street address is 200 Clarendon Street, but occupants also use "Hancock Place" as a mailing address for offices in the building. John Hancock Insurance was the primary tenant of the building at opening, but the company announced in 2004 that some offices would relocate to a new building at 601 Congress Street, in Fort Point, Boston. The tower was originally named for the insurance company that occupied it, which in turn was named for John Hancock, a signatory of the United States Declaration of Independence.