Planning portal doesn't match what I have been told about local area?

[WhirlwindHugs]

This is really bothering me so I wondered if there was anyone with planning experience who can clear this up for me?

I live on a row of 4 terraced houses built on what was farm land. The two middle houses have a fenced and locked pathway that leads to their back gardens.

At the back of the houses was some extra land which was sold off to other local houses to extend gardens etc.

Recently I want on the planning portal (interactive map) for our county and noticed that this access path is marked in green (the colour of public fields etc) and that the area of land behind our house (which is fenced off as part of another neighbours garden) is also shown as a large green area, accesible by this access path.

We had talked about maybe buying this section of land off our neighbours, but now I am wondering if they ever bought it at all?

Does anyone know if it's likely to be a mistake, or how I can find out who owns it?

Best way to find out is to do a Search of the Index Map with the Land Registry. Have a look on the official gov.uk. Land Registry web pages. They have a helpline if you need guidance on how to complete the form. There is a fee payable, but isn't very expensive.