The League of Nations/Société des Nations was established by the Treaty of Versailles in 1919. The League was headquartered in Geneva. Its permanent home from 1920 to 1936 was in the repurposed Hôtel National, renamed Palais Wilson in 1924 after the death of US President Woodrow Wilson. While the US never joined the League of Nations, Wilson played a key role in establishing the League of Nations at the 1919 Paris Peace Conference that lead to the Treaty of Versailles after WW1.
Palais Wilson has a prominent place on the Geneva waterfront, overlooking Lac Léman.
The League of Nations headquarters moved to the purpose-built Palais des Nations in 1937. Palais Wilson ultimately fell into disrepair and was damaged by fire in the 1980s. It was restored and renovated in the 1990s. It is now returned to a role in international affairs, as headquarters for the United Nations Office of the High Commissioner for Human Rights (OHCHR).
I like this description from a March 2004 UN publication:
Today, staff of the Palais Wilson enjoy its glories – a broad lakefront view, high ceilings, wide hallways, a grand entrance and easy access to downtown city streets – along with its oddities: unevenly sized offices, with ceilings too high or too low, squeaky wood parquet floors in many hallways, an out-of-the-way 5th-floor attic with an improvised gym and weight room, a cafeteria view that glares into an adjacent hotel swimming pool, and a main street entrance opening on a narrow cul-de-sac at the end of the No.8 bus line.
(David Winch, Rebirth of a Palais – The Colourful Past and Dynamic Present of a UN Landmark, reprinted in AAFI/AFICS Bulletin, Vol 63, No 4, Sep 2004, p 29)