In the old Jewish ghetto, known as the Giudecca, you can visit an ancient Jewish miqwe (ritual bath) that lies buried 20m beneath the Alla Giudecca hotel. The baths were once connected to a synagogue, but were blocked by members of the Jewish community when they were expelled from the island in 1492. Regularly scheduled tours are offered in English and Italian.
It's a fascinating sight – the three deep pools intended for total immersion constantly bubble with fresh water, which now has to be pumped out of the chamber to prevent flooding. There is a separate, private pool that was for the sole use of the rabbi.
