Which of the following is an example of a lockfast place?

A locked safe is an example of a lockfast place because it represents a space that is secured and deliberately designed to protect its contents from unauthorized access. The term "lockfast place" refers to any location that can be locked, making it difficult for individuals to enter or access. A locked safe exemplifies this concept perfectly, as it is both physically secure and typically intended to hold valuable or sensitive items.

In contrast, the other options do not meet the criteria of a lockfast place because they either lack security or are not designed primarily to be kept locked. An open shed offers no security, as it is accessible without any barriers. A public park is inherently open to the public and is not secured by lock and key. Similarly, while a school gym might have secure areas, it is generally a public facility meant for community access and is not exclusively for private or secure use, thus not fitting the definition as closely as a locked safe does.