An example of a fairly recent little known law is the Mines (Working Facilities and Support) Act 1966. This was highlighted in a recent case involving a polyhalite producer, York Potash.
York Potash identified a significant polyhalite resource for use as fertiliser at its mine in the North York Moors National Park. The only realistic means by which the mineral could be transported was by conveyor in a tunnel. York Potash obtained planning permission for conveyor belts to run in a tunnel from the mine to port facilities on Teesside.
For almost all of the tunnel route, the owners of the land were known and the necessary rights had been obtained by agreement. There remained a small residue of land for which the owners could not be found. York Potash sought the grant of ancillary rights by way of an "underground wayleave, or other right for the purpose of access to or conveyance of minerals or the ventilation or drainage of the mines" under the Mines (Working Facilities and Support) Act 1966. The company had to satisfy the court that the grant of rights was in the national interest, and that it was not reasonably practicable to obtain the rights by private arrangement.
The court agreed and the rights were granted.
This law illustrates that various third parties can have rights over, above and underneath your land. You can't assume that your home is your castle and that you can exclude all others.