1. Hoa Lo Prison, also known as the \"Hanoi Hilton,\" is a historical landmark located in the heart of Hanoi, Vietnam. The prison was built by French colonists in the late 19th century to hold Vietnamese political prisoners who opposed colonial rule. During the Vietnam War, it was used by the North Vietnamese to hold American prisoners of war.

The prison has a notoriously dark history, with reports of torture, execution, and brutal living conditions. The prison’s most famous inmate was Senator John McCain, who was held captive there for over five years. The prison now serves as a museum and memorial to those who suffered and died within its walls.

2. The prison is open daily from 8:00 am to 5:00 pm, with the exception of certain holidays. Their phone number is +84 24 3934 2253.

3. Admission to the museum costs 30,000 VND (approximately $1.50 USD) per person. Visitors can easily reach the prison by taxi or motorbike, as it is located in the city center. There is no public transportation available to the site.