Use these 2 free admission passes to examine over 200 gadgets, weapons, bugs, recording devices, and vehicles at the International Spy Museum in Washington, D.C.  Travel back through the centuries to trace the earliest moments of the world's second oldest profession.  Learn about invisible ink, buttonhole cameras, and ingenious disguise techniques.  Test your skills of observation and surveillance at interactive stations.  Do you have what it takes to be a spy?  When you're done exploring, pick up a nifty gadget in the gift shop and save 20% off your purchase.