The house hidden between two churches in Porto, which thousands of people walk by and don't know it "exists"

In the city center of Porto, Portugal, is a charming house – but thousands walk past it every day without noticing.

The small, 1.5-meter-wide Casa Escondido is located between two churches – Igreja dos Carmelitas and Igreja do Carmo – and is the city's 'narrowest house'.

The building looks like one large church at first glance – but it is actually three separate buildings, the Telegraph reports.

The house itself is so thin that it almost looks like a wall, characterized only by a simple green door and two windows, meaning it is hidden.

The unique structure was featured in an episode of George Clarke's Amazing Spaces on Channel 4.

Built in 1768, the property was surprisingly spacious, with a living room, bedroom and study – it looked like something out of Harry Potter.

“Now this is amazing,” George said as he walked in. The door on the front facade is only a little over a meter wide. It actually just opens a little and gets a little wider.

Inside there were impressive spiral staircases, as the building extended over three floors.

George explained that the church on the left was built for Carmelite nuns in the seventeenth century, with the church on the right for monks in the eighteenth century.

The “secret house” in the middle was supposedly built to separate monks and nuns – while other local rumours suggest it may have been due to legal regulations stating that two churches could not share a wall.

"What's amazing is that inside, it's so simple. You have two decorative churches on either side, and in the middle there's just whitewashed walls, wooden floors. It's like being in a monk's cell. Thousands of people must walk past this building every day and have no idea it's there," George explained.

The property was inhabited until the 80s by chaplains, artists, doctors and the churchwarden. Curious travellers can also take a look at the house, with tickets costing five euros including access to the museum. /Telegraph/