Publisher's Weekly (Starred Review)
This book's intriguing topic and delightful presentation by its knowledgeable and eccentric authors will enthrall New Yorkers and non-New Yorkers alike. Deyo and Leibowitz, editors at Jinx, a zine devoted to the urban exploration movement, illumine what drives them to explore cities' infrastructure, the places few consider going (including sewage systems, subway tunnels and bridge spans). A charming pastiche of Alice in Wonderland and The X Files, this is both a paean to New York and a chronology of a love affair with the unusual. The authors take readers on a hike to Manhattan from the Bronx via the Croton Aqueduct, which was one of the major engineering feats of the 19th century, providing water for most New Yorkers. They also traverse the tunnels under Riverside Park to find the so-called mole people who live in the Amtrak system and to seek out graffiti artists. A semi-break-in takes readers into the Roosevelt Island Smallpox Hospital. Other treks include exploring a condemned building in East Harlem, a nondiplomatic maneuver at the United Nations and climbing to the summit of the George Washington Bridge. Rife with literary quotations, historical and scientific tidbits, political and social commentary plus a plethora of details about the explorations the authors and their strange cadre have made (despite the muck and mire, the men always wear suits and ties and the women cocktail dresses), this smart, quirky book will delight spelunkers, couch potatoes and all in between.Copyright 2003 Reed Business Information.

  Wired Magazine
A gang of intellectual misfits sets out to explore the city's perilous, concealed places - from the bowels of an abandoned aqueduct to atop the steal girder of the George Washington Bridge. As the team shimmies into dank and narrow spaces, homages to the likes of Nikola Tesla are interwoven with humorous tales and tirades. The human ingenuity is palpable, and its beauty is owed to engineers. - Heather Sparks

Boston Globe
I still have dreams of discovering secret places and was visited by a frisson of exhilaration on spotting Invisible Frontier: Exploring the Tunnels, Ruins, and Rooftops of Hidden New York,'' by L. B. Deyo and David ''Lefty'' Leibowitz (Three Rivers, paperback, $14.95). The authors are the creators of Jinx, a magazine devoted to ''Worldwide Urban Adventure,'' which comes down to trespassing with style. The two heroes insist that formal dress be worn in the field: suits and dark glasses for males, and black cocktail dresses for females... these are young people in rebellion against their own generation's Zeitgeist, the bored, apathetic spirit that emanates from ''the mouse, the flip-flop, and the casual Friday.''

...Deyo and Leibowitz are driven, and what they do is immensely exciting. They and their teams of snoopers have visited the roof of City Hall and, far below, its original, now abandoned, subway station. They have also explored, among other places, a derelict row house in Harlem, a ''semiretired'' aqu educt, the crumbling Gothic pile that was the smallpox hospital on Roosevelt Island, and the highest point on the George Washington Bridge - this on Sept. 9, 2001, the last expedition recorded here. Though they say nothing about it, one feels that Sept. 11 put a crimp in further explorations of New York's essential infrastructure.

Robert Dumas
The author V. S. Naipaul said we only have room in our lives for six or seven great book love affairs. I’m not yet sure if what I experienced in the past twenty-four hours qualifies, but if it doesn’t, then man, is it ever close.

I’ve just finished reading L. B. Deyo and “Lefty” Leibowitz’s awesome Invisible Frontier and all I can say is that it is incredible. A group of self-described “urban explorers”, calling themselves the Jinx Society, go on various missions to such places as the Old Croton Aqueduct, the smallpox hospital on Roosevelt Island, the top of the Tweed Courthouse, the hospital on North Brother Island where “Typhoid Mary” Mallon lived out 24 of her last 26 years on earth, the tops of the Queensboro and George Washington Bridges, the “Freedom Tunnel (a stretch of Amtrak tunnel running north from Grand Central Station underneath Riverside Park, named for “Freedom Chris”, a legendary grafitti artist), the old City Hall subway station (a monument to artistic architecture in—of all things—a subway station) and all the other places the average person is not supposed to be.

The descriptions of their adventures are entertaining and they provide just the right amount of backstory to each adventure to make me want to go look up more on the topic. The explorers, especially Deyo and Leibowitz, have extensive knowledge of New York’s infrastructure and history, which they use, sometimes to enlighten, other times to simply rant at how we’ve lost something.

I feel it, too. Walk down your average street in Manhattan and look up; virtually every building built before the end of the Second World War has some sort of ornate decoration on it; a roof-ledge held up by ornate Ionic stone scrolls, beautiful window-caps and so on and so forth. Now look at your average building built in the second half of the Twentieth or the early Twenty-First Century; most often, they are utilitarian, devoid of any real artistry. Architecture today is soulless and perpetuates a feeling of only one thing; corporate encroachment upon the lives of the public.

It is virtually impossible to walk into Grand Central Terminal’s main concourse without being astounded at its beauty; the high ceiling, the incredible painting on the ceiling, the sheer love that went into its creation. See if anyone can say the same about the modern Pennsylvania Station across town; a long hallway, with only one large space in the whole of it, one that is not even a tenth as large as Grand Central’s. I find it to be almost insulting that as I walk down the stairs to the Long Island Rail Road, I see a sign on the wall with an side-view illustration of the old (pre-Madison Square Garden) Penn Station and the words YOU ARE HERE in red beneath it. The old Penn Station was as beautiful as its sister, Grand Central, and it took them three years to destroy that beautiful old edifice to make way for the garish Madison Square Garden and One Penn Plaza. Look through The Destruction of Penn Station to get an idea of what I mean.

There is beautiful architecture all around you when you are in New York. Invisible Frontier helped me to see that a little bit better, and I thank its writers for braving life and limb to find a little bit of the city we New Yorkers lose a little more every day.-OBNOXIO.US