The Maison de la Paix is located at Chemin Eugène-Rigot 2B, on the corner of Avenue de France, a few minutes walk from Place des Nations and the Jardin Botanique. 

By air
Geneva Airport has many direct flights from Europe, as well as some from North Africa, the Middle East, North America and Asia.
The airport is located 15 minutes away from the Maison de la Paix by public transport, or 10 minutes by taxi. Take the train (4 per hour) to the main Geneva station “Gare Cornavin” and then the tram (see below). Alternatively take bus 5 or 28 to the stop “Nations” (12 per hour) and then walk 3-4 minutes down Ave de France.
more info: Geneva airport

By tram
Tram 15 will take you from the main Geneva railway station “Gare Cornavin” to the stop “Maison de la Paix” in about five minutes. The Maison de la Paix is about two minutes’ walk from the tram stop, just across the railway bridge. Trams run every five minutes during the day.
Single tickets cost CHF 3, and are valid for one hour, from anywhere in Geneva.  A day-pass (from 9am until midnight) costs CHF 8, while a 24-hour pass costs CHF10.
more info: Geneva public transport

By train
Geneva's main station, "Gare Cornavin", has direct connections from many cities in Switzerland and France. The station is a 15 minute walk from the Maison de la paix; or take the tram (see above).
more info: Swiss railways

Download the directions to the WBCSD office here - (PDF)