Matti Friedman, writing for the AP, describes the various “underground tours” that are open to tourists in Jerusalem.  He also touches on the political and religious complications.

Underneath the crowded alleys and holy sites of old Jerusalem, hundreds of people are snaking at any given moment through tunnels, vaulted medieval chambers and Roman sewers in a rapidly expanding subterranean city invisible from the streets above.
At street level, the walled Old City is an energetic and fractious enclave with a physical landscape that is predominantly Islamic and a population that is mainly Arab.
Underground Jerusalem is different: Here the noise recedes, the fierce Middle Eastern sun disappears, and light comes from fluorescent bulbs. There is a smell of earth and mildew, and the geography recalls a Jewish city that existed 2,000 years ago.
Archaeological digs under the disputed Old City are a matter of immense sensitivity. For Israel, the tunnels are proof of the depth of Jewish roots here, and this has made the tunnels one of Jerusalem’s main tourist draws: The number of visitors, mostly Jews and Christians, has risen dramatically in recent years to more than a million visitors in 2010.
But many Palestinians, who reject Israel’s sovereignty in the city, see them as a threat to their own claims to Jerusalem. And some critics say they put an exaggerated focus on Jewish history.

The story continues here.  The underground “route” that Friedman describes begins with a walk through Hezekiah’s Tunnel (or its alternate, the Siloam Tunnel).  Then, later this summer, one will be able to enter the Roman drainage system and walk all the way to the Western Wall plaza.  In several years, a new route will take visitors on the first-century street beneath the prayer plaza.  That will link up with the Western Wall tunnels which run north along Herod’s well-preserved retaining wall.

For more of the political angle on the “Underground Jerusalem” excavations, see last month’s article in Haaretz (noted here).  For some additional photographs, see Leen Ritmeyer’s post.

HT: Joseph Lauer