Ghost towns are among the eeriest locations on Earth; places where once bustling towns are now filled with an unnerving silence. Walking through these towns makes it easy to see why people left; some due to war, others because of freak accidents. But what about the ones that were abandoned for no reason? Why would everyone just up and leave? Below are five towns that people left and no one knows why.

1. Roanoke Colony, North Carolina: Disappearing Act

The Roanoke Colony is one of the biggest mysteries in U.S. history, so much so that people are still baffled, even to this day. Sometime in August 1587, a group of 115 English settlers arrived on Roanoke Island with the hope of starting a new life. Following a three-year departure to England for fresh supplies, governor John White made a shocking discovery: everyone was gone, including his daughter and granddaughter. It is speculated by some historians that the colony relocated to what is now known as Hatteras Island.

2. Inis Cathaigh, Ireland: Forgotten Island

Tourists visiting the Irish island of Inis Cathaigh immediately get a sense of what life there must have been like before everyone relocated. There are plenty of ruins that capture the attention, including an old monastery, an Irish round tower and a ruined artillery building. The island’s history is a long one that goes all the way to 1842 when it was home to a handful of families, mostly Shannon Estuary pilots. They even thrived during the famine, but by 1969, they were all gone. What’s weird is that there are no clues as to why they left and it might be something we may never understand.

3. Dudleytown, Connecticut: The Dark Forest

In the forested Connecticut town of Cornwall lies a private area known as the “Dark Entry Forest” where the citizens of “Dudleytown” once lived. There are a number of theories as to why the town failed. The first is that some people may have left to look for work after the local iron industry died down. And the other one is a bit spookier: it’s said that the early English settlers brought a curse with them that caused anyone living in Dudleytown to go insane, due to the presence of ghosts and demons. As you could imagine, this place became a hotspot for amateur ghost hunters and paranormal investigators.

4. Rhyolite, Nevada: Glass Bottle Buildings

Rhyolite, Nevada was once a vibrant town that initially started as a mining camp in 1905 following the discovery of gold in the area. It didn’t take long for the town to find its footing and by 1907, there were already schools, electric plants, stock exchanges and a board of trade. They even built a house with 50,000 discarded beer and liquor bottles that still stands today! So, what went wrong? Well, it may have had something to do with the steady decline of millwork, which forced residents to look for jobs elsewhere.

5. Ordos Kangbashi, China

It would be wrong to call Ordos Kangbashi a ghost town, because it technically isn’t one as there are nearly 70,000 people living there. But it’s so quiet that one might think that it’s a ghost town. It isn’t, but the city’s sheer size makes the place seem like it’s been abandoned. And at one point it truly was. This was due to a number of issues such as high property taxes and construction delays. Their original goal was to have 200,000 people there by 2020, but clearly that never happened.