A mine entrance is technically an 'adit'
adit
The vertical rows on the periodic table are called groups.The vertical rows are called periods and the horizontal columns are called groups.
Shaft mining or shaft sinking refers to the method of excavating a vertical or near-vertical tunnel from the top down, where there is initially no access to the bottom.
The huge steel structures above a gold mine that drive the skips are called headframes or winding towers. They support the hoisting equipment used to lift ore and waste from underground. Headframes are critical for the operation of vertical shafts in mining operations.
An adit. In North America, the horizontal or sloped entrance to a mine is called a "Portal". Portal more specifically refers to the portion of the shaft visible from the outside of the mine. In some areas, the Portal portion of a horizontal shaft is called the "Drift Mouth" or "Drift Portal" as this shaft leads into a "Drift Mine". With a vertical shaft, that portion would be called a "Collar".
A mine entrance is technically an 'adit'
Adit
Adit
Adit
The horizontal entrance is called a portal. If there are two portals, then you call the excavation a tunnel. If there is only one, it is call a drift or adit.
The entrance to underground mines is called a portal or adit. It is the point of access for miners and equipment to enter and exit the mine.
A horizontal entrance to a mine is known as an adit.
adit
A shaft is a hole dug in a mine.
Adit
at the entrance to Merry Vale there is a rich tin vein mine and get garnet there