wikipedia Zilpah
wikipedia Tomb of the Matriarchs ... Note how Bilhah & Zilpah are described as handmaidens instead of wives by wikipedia but on the actual Tombstones they're referred to as Jacob's wives.

According to Jewish tradition, Zilpah is believed to be buried in the Tomb of the Matriarchs in Tiberias. Went there in November 2011 and took the following pictures (Eddie):