Both are above Halifax Borough Market, running alongside the roof of the market looking out onto the streets of Halifax.
Amazingly, the houses there are still used by the businesses below and a couple are still lived in.
Neither streets are usually open to the public but Calderdale Council often organises special tours so that people can take a look for themselves.
These are usually part of the town’s Heritage Festival and include exploring the unique architecture of the Grade II listed Halifax Borough Market and learning about its history.
Courier photographer Charles Round took these photos of the secret streets when he went up there a few years ago.
1. Halifax Heritage Festival: Take a look at Halifax town centre's two secret 'streets in the sky' and find out how you can see them for yourself
The entrance to the streets from Market Street in Halifax town centre Photo: Charles Round
2. Halifax Heritage Festival: Take a look at Halifax town centre's two secret 'streets in the sky' and find out how you can see them for yourself
The streets are accessible by stairs Photo: Charles Round
3. Halifax Heritage Festival: Take a look at Halifax town centre's two secret 'streets in the sky' and find out how you can see them for yourself
One of the secret homes above Halifax Borough Market. Photo: Charles Round
4. Halifax Heritage Festival: Take a look at Halifax town centre's two secret 'streets in the sky' and find out how you can see them for yourself
People viewing one of the uninhabited homes of the "streets in the sky" Photo: Charles Round