The “Green Building” hosts the global headquarters of the UN Environment Programme and UN-Habitat, the Human Settlements Programme. Bookings are made in combination with the walking tour.

Have you ever wondered what UN Headquarters was like during the Cold War? Find out this summer by taking a special tour based on the novel "An UNwilling Spy".

The city’s most impressive building, the sanctuary of the Heliopolitan Jupiter, boasted 65-foot-tall columns placed atop 3,000-ton stone blocks, according to Elif Batuman of the New Yorker.