In a relatively remote corner of the Inn, far away from any of the main attractions, Lex built a cabin. The cabin itself wasn't too large, with 3 individual bedrooms and one living room that also had a kitchen in it. If anything, the unique part of this cabin was the secret basement. The entrance to the basement was completely hidden and could not be detected, as arranged by Lex, by using his powers, so that if Remy ever needed to bring someone else into the cabin, they would never detect the opening.
A vertical ladder from the opening led into the first room of the basement was just one that led to four other rooms. This is where the real magic of the Inn shone, as building the specifications of those rooms would require extensive engineering and labor, along with expensive and rare materials. Yet Lex was easily able to isolate the unique environments in each room.