Saint-Germain-en-Laye (săN-zhĕrmăN´-äN-lā), town (1990 pop. 41,710), Yvelines dept., N central France, on the Seine River, a residential suburb W of Paris. It is the last station on the express subway system from Paris. The town, a resort, is known primarily for its 16th-century Renaissance château, built by Pierre Chambiges, which was a royal residence until the French Revolution and now houses the major museum of pre-Christian antiquities in France. Henry II and Louis XIV were among the kings born in the château; Louis and his court resided there until 1682. The magnificent château park was designed by André Lenôtre. Several important treaties (most notably the 1919 Treaty of Saint-Germain) were signed in the town. Claude Debussy was born there.