The K-25 Portal Checkpoint in Tennessee is a point of interest that is definitely worth a visit during a national park tour. This area is a part of the Manhattan Project National Historical Park and is a unique glimpse into the history of the Cold War era.

The K-25 Portal Checkpoint was once a top-secret area that played a significant role in the production of weapons-grade uranium for use in nuclear bombs. Today, visitors can see the remains of the checkpoint, including the guardhouse and a replica of the "badge" that workers had to carry to access the site.

One of the unique things that visitors can see at the K-25 Portal Checkpoint is the actual equipment that was used to enrich uranium during the Manhattan Project. This machinery is enormous, and it's fascinating to see how it was used to produce nuclear material.

Another reason to visit the K-25 Portal Checkpoint is to learn about the daily life of workers during the Manhattan Project. Visitors can learn about the working conditions, the safety protocols that were put in place, and the cultural impact that the project had on the surrounding area.

Overall, the K-25 Portal Checkpoint is a fascinating destination that offers a unique glimpse into an important period in American history. Whether you're interested in science, history, or just curious about the unknown, this point of interest is definitely worth a visit.