A horizontal entrance to a mine is known as an adit.
Adit
Puzzle No 66: The Locked Box, Location: Mine Entrance. Answer = Turn the Red dial to numbers 2,7,1, and 4.
3 letters? 4- MARA (mine) then 3-TLS (The Lonely Spartan)
tv presenter 4 and 4
Go to this link this is not mine though.What_animals_are_six_letters_longSorry but it is a list that may include some creatures with more than four legs.
moth
No US states have a capital with only 4 letters; they all have 5 letters or more.
ali baba
A plate that has four letters is HOME plate.
Ogen
carp
Four letters, V I I I
Another name for malaria that starts with an A and has 4 letters is ague.