Open House NYC opens doors once a year to places and spaces that would normally remain inaccessible to the public. Architectural masterpieces, landmark buildings, bike sheds, closets and cloisters join a worldwide movement to share an appreciation for our built environments. It is a fantastic opportunity to explore. Although some hotspots like the Trinity Church bell tower or the Citi bike warehouse require advance bookings with a $5 ticket, most places are free. Either way, you need to get your treasure map early and plan ahead because there are a lot of curious people in NYC and only two days to get in line.

The Jefferson Market Library on 6th Avenue and 10th Street is an extraordinary structure of red bricks, turrets and gargoyles, with stain glass windows and ebony door frames perfectly preserved inside. Built in 1877 when that part of the city was very poor, the building has been described as a Bavarian trifle and is a living testament to the power of perks. Boss Tweed was the politician who signed the checks in those days and contractors seeking favour provided him with all manner of extravagance, including the now landmarked tower with four faced clock and bells. Originally constructed as a courthouse, the building later became a women’s house of detention where Mae West was tried on obscenity charges ( The Society for the Suppression of Vice objected to her Broadway play called ‘Sex’ ).

After such grand beginnings, the building deteriorated with less distinguished guests and may have languished completely had it not been for the clock. Stuck at 3.20 for 40 years, the locals – including E.E. Cummings – decided it was time to move on. The building was completely renovated in the 60’s to accommodate a community based modern library and more recently the tower has become a destination for Open House NYC.

A wait of well over an hour was easily worth it for the experience of squeezing up the spiral staircase of 149 steps and emerging into a vault that then wound you to the fire watchers balcony. Inside there was dust everywhere, attributing the space more points for history than housekeeping, and providing a picture perfect stream of sunshine unchanged for 136 years. It was all too much for a woman who froze in a panic attack at the top of the stairs – we had to stop all traffic in and out as modern paramedics met the challenge of how to get her down.

A spider now lives in the the tower and each Halloween is dangled over the turrets to inspire stories of ghosts past. With 360 degree views over Greenwich Village you can imagine what those ghosts may have seen. Although not on public display, scrawled on the inside of the original bell are the words To hell with Spain, remember the Maine 1898, a rally cry leading to the Spanish American war. Banksy may somehow tag a modern twist to this historic graffiti which will be discovered when the tower throws open its doors again. But in the meanwhile, get out your gold detectors, Australia claims four of the twenty cities that participate in Open House Worldwide – and who know what you may find…