Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Rooms ( decor VARCHAR, RoomId VARCHAR )
TABLE: CREATE TABLE Reservations ( Room VARCHAR )

### Question ###
What kind of decor has the least number of reservations?

### Accurate SQL ###

SELECT T2.decor FROM Reservations AS T1 JOIN Rooms AS T2 ON T1.Room = T2.RoomId GROUP BY T2.decor ORDER BY COUNT(T2.decor) LIMIT 1