NYC
03/18/2010 05:12 am ET Updated May 25, 2011

Open House New York Map

This weekend marks the 7th Annual Open House New York, when the city opens its doors to the public, giving free tours of some of its most famed architectural landmarks.

From Radio City Music Hall to the tunnels of the Atlantic Avenue subway station, the event winds from the city's greatest heights down to its core.

And did we mention it's free?

Some locations require reservations, and all have limited space. Go to www.ohny.org for full details.