Results: Shhh...Don't Tell! (Part 1 of 6)

Waldorf Astoria, New York City, New York - Most visitors to New York know Waldorf Astoria as a swanky hotel dripping in old-school luxury. But, beyond its chandeliers, vaulted corridors and uber-luxe lobby, the hotel hides a secret or two – not least the train station that exists beneath its plushly carpeted floors. It has become known as Track 61 and was used by VIPs, including President Franklin D. Roosevelt, who purportedly wanted to hide his polio disease. There are rumors that the station is still occasionally used today too. Were you aware of this secret?

Disneyland Resort, Anaheim, California - No matter how many times you've been to Disneyland's parks, there's always something new to discover – a hair-raising ride, a freshly debuted show or, perhaps, the uber exclusive Club 33. This private-members' club is tucked away behind an unmarked door in New Orleans Square and there's apparently a hefty waiting list and a whopping price tag. The coveted few who make it inside can expect tasting menus, cocktails and tip-top hospitality and entertainment. Were you aware of this secret?

House of the Seven Gables, Salem, Massachusetts - Salem's House of the Seven Gables, inspiration for Nathaniel Hawthorne's gothic novel of the same name, is shrouded in mystery as it is. The 17th-century home, with its eye-catching gables and shadowy corners, is inherently linked with the supernatural conjured up in Hawthorne's novel. But adding to the intrigue is the fairly recent restoration of an off-limits 'secret room', thought to have been a dining room chamber. There's also a 'secret staircase', which winds its way to the attic. Were you aware of this secret?

Lincoln Memorial, Washington DC - This columned memorial in DC's National Mall is a tribute to one of America's late, great presidents, Abraham Lincoln. Yet, while tourists usually come to see this monument in their droves, there's something they might not know. Underneath the landmark, there's an enormous undercroft (a kind of bunker-like basement area) filled with columns that support the structure. Tours were offered here during the late 1970s and 1980s, but these were stopped due to asbestos. Nevertheless, there have been reports that the NPS now plan to revamp the subterranean space. Were you aware of this secret?

Gateway Arch, St Louis, Missouri - You can't miss this mammoth arch presiding over St Louis' waterfront – in fact, it's the tallest man-made structure in the States. But this giant is not without its secrets. It's said that, before the crucial keystone was hauled into place in the 1960s, a time capsule was welded into it. The capsule purportedly contains the signatures of more than 760,000 residents, as well as other unidentified items. Were you aware of this secret?