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_204_278 ( id number, "name of president" text, "picture" text, "life span" text, "year of presidency" text, "place of conference" text )

### Question ###
which location had the most conferences listed ?

### Accurate SQL ###

SELECT "place of conference" FROM table_204_278 GROUP BY "place of conference" ORDER BY COUNT(*) DESC LIMIT 1