One must look closely to see it: a wire that covers 13 miles around Palo Alto, from Hwy. 101 to Foothill Expressway, between Adobe and San Francisquito creeks.
Constructed of super-strength fishing line (used for catching sharks), the eruv, which was completed in early September, has been a dividing line between faith and the state to some since it was first proposed eight years ago.
Heated arguments erupted over its potential violation of the U.S. Constitution's separation of church and state.
But the eruv, a linear boundary that allows Palo Alto's Orthodox Jews to carry young children and objects in public spaces during the Sabbath, is a unifier, encompassing all of the community and expanding home into the greater public realm, some said.
Its existence in Palo Alto today is an example of the First Amendment of the Constitution in action: Freedom of religion regardless of how small the minority, according to some members of the religious community.
Carrying anything in public places is considered a form of work and is forbidden on the Sabbath by Jewish law. That includes young children who are not yet able to walk, according to Rabbi Yosef Levin, executive director of Chabad of Greater South Bay. Mothers whose young children are unable to walk on their own had to stay home with the children, which limited access to synagogue services and other gatherings, since the children and belongings could not be carried.
But the eruv has changed all that for Palo Alto's Orthodox Jews.
"Rivka" (not her real name), a young mother, said the eruv has enabled her family to go out together during the Sabbath.
"It's made a huge difference in our lives. It's really wonderful. The main thing is the kids who don't walk yet. You can take a stroller. We can be out and about more. It's hard to describe the difference to someone who doesn't observe (the laws)," she said.
Before the eruv, Rivka and husband, "Jacob," had to take turns going to synagogue. And an outing to a park in the afternoon with friends meant that either she or Jacob would go with the older kids and the other parent would stay home with the baby, she said. Even diapers were not allowed to be carried, which meant leaving them in places where they could later be retrieved if the couple was away from home during the Sabbath.
When her son was born, Ilana Goldhaber-Gordon, who practices Conservative Judaism, made the decision not to observe the restrictions on carrying. But she grew up in a family that did observe the carrying rule.
"My mother couldn't go to synagogue. A big part of the Shabbat (Sabbath) experience is inviting families to get together. We couldn't reciprocate because we couldn't take the baby off of the property," she said.
The idea of the eruv dates back to the writings of the prophets -- that people shouldn't carry from the private to the public domain during the Sabbath, she said. It was designed to make the day of rest truly free of laborious activity.
But certain activities are allowed in the home, and because creating an eruv symbolically turns the whole community into the private sphere public spaces become an extension of the home, she said.
"The eruv reminds us we are all one community. ... It's entirely about the human community, not just putting up a string. There must be a sharing of bread -- of community and inviting guests and sharing foods. The eruv speaks to those three elements," she added.
While widely lauded by the Orthodox and Conservative communities, the long, eight-year struggle and the firestorm surrounding the eruv has taken a toll on many in the Jewish community.
Rivka and Jacob, like many others, were reluctant to discuss the eruv -- even its benefits -- because of lingering feelings after its controversy, and they only spoke on condition of having their names changed.
For Rabbi Yitzchok Feldman of Congregation Emek Beracha, who spearheaded the move to create a Palo Alto eruv in 1999, the pain of the controversy and anti-Semitic vitriol is still raw. Feldman would not discuss the eruv now, seeing no benefit but to stoke the passions of those who are still against it, he said.
The eruv cost more than $150,000, according to a newsletter distributed to Emek Beracha members.
As of Sept. 12, nearly $100,000 in debt was still outstanding for its construction, but $50,000 in matching donations is being offered. All of the costs are borne by Palo Alto Community Eruv, Inc., which also maintains the eruv.
Eliot Klugman, a 30-year Palo Altan and member of Congregation Emek Beracha, said the hefty price tag is worthwhile.
"As a resource, as a long-term investment, it is absolutely unbeatable," he said.
He estimated hundreds of families benefit from the eruv. While that number may seem small compared to the city's 62,000-plus population, the eruv will strengthen the city's Jewish community, as more people will want to move here now that the boundary has been constructed, he said.
"It will last 50 years. By then it will be paid for in terms of its benefits, in terms of the people coming to the area," he said.