The Ramsar Convention is the world's longest-standing international treaty for wetland and waterbird protection. Signed in Ramsar, Iran, in 1971, the Convention on Wetlands of International Importance Especially as Waterfowl Habitat has to date been signed by 172 countries, which have agreed to engage in "working together for wetland conservation and wise use" in more than 2,500 protected areas covering over 2.5 million square kilometers (965,000 square miles) around the world. However, the Ramsar Convention's measures are not legally binding, leaving open the possibility that many Ramsar sites may be akin to "paper parks"—protected in theory, but not in reality.