This category is for the Lonely Mountain.
“The Side-door or Secret Door was a secret entrance to the Dwarven kingdom of the Lonely Mountain...Side-door
“The Secret Tunnel was a long indoor tunnel leading to the Bottommost Cellar, the lair of Smaug...Secret Tunnel
“The Bottommost Cellar or Smaug's Lair was a hall and the lowest level of the Lonely Mountain. It...Bottommost Cellar
“The Front Gate was a common term for the Gate of Erebor, the wide arched main entrance of the...Front Gate