Many ritual baths from the Second Temple Period have been excavated in Jerusalem, but today (Wednesday, 5 August 2015) the Israel Antiquities Authority announced the excavation of one in the Arnona neighborhood in south Jerusalem. This large mikveh has inscriptions, written in Aramaic, and symbols of a boat, palm trees, plants and possibly a menorah written or carved on its walls!
The Times of Israel has published an article describing this discovery along with 9 clear photos and an informative (partially in Hebrew) 5 minute video of the exterior and interior of the mikveh and its inscriptions.
HolyLandPhotos' Blog 