Erected in 1995, these six glass towers spring up in the midst of attractions that celebrate freedom, reminding visitors of the consequences of a world without it. The pattern on the glass, which at first appears merely decorative, is actually 6 million random numbers, one for each Jew who died during the Holocaust. As you pass through, pause to read the inscriptions.

To continue on the Freedom Trail: The trail passes under the expressway through widespread Big Dig construction (you might not be able to find the trail -- ask the police officer at the corner of Hanover and Blackstone sts. for help if you get lost) and emerges in the North End. Follow Cross Street to Hanover Street, turn left, and follow Hanover to Richmond Street. Turn right, go 1 block, and turn left.