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 table_name_57 ( year_opened VARCHAR, coaster_name VARCHAR )

### Question ###
Which year opened has le monstre coaster?

### Accurate SQL ###

SELECT year_opened FROM table_name_57 WHERE coaster_name = "le monstre"